Supplements
Food first. Supplements fill specific gaps — nothing more. The supplement aisle is a chaotic mix of strong science, lab artifacts, marketing fiction, and everything in between. Evidence quality varies enormously from shelf to shelf, and the only honest way to navigate it is to tier compounds by what the evidence actually supports.
This article sorts them into four tiers, from the highest-confidence daily basics (omega-3, vitamin D3, magnesium, creatine — backed by RCT-level evidence most adults benefit from) down to the speculative experiments and outright skips. If Tier 1 isn't in place, don't bother with Tier 3. The foundation comes first.
Order of operations: Tier 4 supplements work best when Tiers 1–2 are already in place. NAC provides cysteine for glutathione, but glutathione also requires glycine and magnesium-dependent enzymes. Sulforaphane activates Nrf2, but the Phase II enzymes it upregulates need zinc, selenium, and B vitamins to function. Build the foundation first.
Tier 1 — Daily Basics (Strong RCT Evidence)
These have the strongest evidence base across multiple meta-analyses. Most adults benefit. Take these unless you have a specific contraindication.
Omega-3 (EPA + DHA)
Strong EvidenceWhy It Matters
EPA and DHA are the biologically active omega-3s — they resolve inflammation, build brain cell membranes (DHA is ~40% of brain phospholipids), protect cardiovascular health, and support retinal function. Plant-based ALA (from flax, chia, walnuts) converts to EPA at only 5–10% and to DHA at <1%. Vegetarians and low-fish eaters consistently have inadequate EPA/DHA levels.
Algae vs. Fish Oil
A 2025 randomized double-blind trial (74 adults, 14 weeks) confirmed algae oil is statistically non-inferior to fish oil for bioavailability of both DHA and EPA in plasma phospholipids. Algae oil is also free from mercury, PCBs, and other ocean contaminants. It tends to be higher in DHA than EPA (opposite of fish oil), which is arguably preferable for brain health.
Dose: 250–500 mg combined EPA + DHA as a minimum. 1,000–2,000 mg for anti-inflammatory effects.
Test: Omega-3 Index (% of EPA+DHA in red blood cell membranes). Aim for 8–12%. Most Western populations are at 4–5%.
Vitamin D3 (Cholecalciferol)
Strong EvidenceVitamin D is a steroid hormone, not just a bone vitamin. It modulates innate and adaptive immunity, regulates autoimmunity risk (MS, Type 1 diabetes, psoriasis), and influences gene expression across hundreds of pathways. The USDA found no dietary pattern provides adequate vitamin D from food alone.
UVB on bare skin synthesizes vitamin D, but this requires midday sun on bare arms/legs — which indoor-heavy lifestyles rarely provide consistently. See Light & Circadian for the sunlight angle.
Form: D3 (cholecalciferol) is significantly more effective at raising serum 25(OH)D than D2 (ergocalciferol). Take with a meal containing fat for absorption.
Dose: 2,000–5,000 IU daily for most adults to reach 40–60 ng/mL. Adjust based on blood levels.
Test: Serum 25(OH)D. Aim 40–60 ng/mL (100–150 nmol/L). Test twice yearly — end of winter and end of summer.
Vitamin K2 (MK-7)
RCT EvidenceK2 directs calcium into bones and away from arteries by activating osteocalcin (bone mineralization) and Matrix Gla Protein (prevents arterial calcification). Without K2, supplemental D3 + calcium can actually worsen arterial calcification. A 3-year RCT in 244 postmenopausal women showed 180 mcg MK-7 daily halted age-related arterial stiffening.
The D3 + K2 pairing: Always take K2 with D3. D3 increases calcium absorption; K2 tells the calcium where to go.
Dose: 100–200 mcg MK-7 daily. Take with fat for absorption.
Food sources: Natto (by far the richest), hard cheeses, egg yolks.
Magnesium
Widespread GapMagnesium is a cofactor in 300+ enzymatic reactions including CYP450 function (Phase I liver detox), ATP production, DNA repair, GABA receptor function (sleep/calm), and muscle relaxation. An estimated 2.4 billion people (31% globally) don't meet recommended magnesium intake. A landmark 2018 review called subclinical magnesium deficiency "a principal driver of cardiovascular disease."
Modern Diet Problem
Soil depletion has reduced magnesium in crops 20–30% since the 1950s. Refined grains strip 80–97% of magnesium. Water treatment removes it from drinking water.
Forms Matter
| Form | Best For | Notes |
|---|---|---|
| Glycinate | Sleep, calm, general use | High absorption, doesn't cause loose stools |
| Threonate | Cognitive function | Crosses blood-brain barrier |
| Citrate | Constipation / Phase III elimination | Good absorption, mild laxative |
| Oxide | Avoid | Poor absorption, mostly laxative effect |
Dose: 200–400 mg elemental magnesium daily. Split AM + PM. Glycinate or threonate at bedtime for sleep.
Test: Serum Mg is nearly useless (only 1% of body's Mg is in blood). RBC magnesium is better — aim for top quartile of reference range (5.5–6.5 mg/dL).
Creatine Monohydrate
Strong for Vegetarians, Older, Sleep-DeprivedCreatine is the body's rapid-energy currency. Phosphocreatine acts as a local battery — instantly donating a phosphate group to regenerate ATP. Your brain uses ~20% of your total energy budget despite being ~2% of body mass. Vegetarians have measurably lower muscle AND brain creatine stores, confirmed via MRS brain imaging.
Where the Benefit Is Strongest
| Study | Design | Dose | Result |
|---|---|---|---|
| 2024 Meta-analysis (Frontiers in Nutrition) | Review of adult cognitive trials | 3–20g | Benefits most consistent in older adults, sleep-deprived, vegetarians |
| 2025 Alzheimer's pilot (KUMC) | 20 patients, 8 weeks | 20g/day | Brain creatine +11%. Cognition improved on multiple composites |
| Sleep deprivation (Sci Reports 2024) | Single dose | ~25g | Improved processing speed + working memory beyond wake baseline |
| Vegetarian cognitive study (BJN) | 45 vegetarians, 6 weeks | 5g/day | Improved processing speed in vegetarians. 20g improved memory in vegetarians but NOT omnivores |
| Dose-response (Brain Sciences 2023) | Healthy young adults | 10g vs 20g | No significant improvement at either dose — tempers the hype |
The EFSA Rejection — The Most Important Recent Finding
In late 2024, the European Food Safety Authority formally rejected the "creatine improves cognitive function" health claim. They found acute cognitive effects only at 20g/day, not at 3–5g. "A cause-and-effect relationship has not been established." This is the regulator that reviews food claims for the entire EU — they looked at the full evidence base and said no.
Kidney Fears Are Overblown
A 2025 systematic review and meta-analysis found creatine does NOT harm kidney function in healthy individuals. The serum creatinine increase is a measurement artifact — creatine, not creatinine.
What's Overstated About Creatine
The muscle and strength evidence is genuinely strong — decades of RCTs, consistent effect sizes, safe long-term. The brain/cognitive claims are oversold. EFSA formally rejected the cognitive health claim in 2024. The clearest cognitive signal is in sleep-deprived people, older adults, and vegetarians — not healthy, well-rested omnivores. The dose-response study (Brain Sciences 2023) found no improvement at 10g or 20g in healthy young adults.
"Creatine for cognition" is a reasonable bet for specific populations, not a universal nootropic. For muscle, take it. For brain, temper expectations unless you're in a high-signal group.
Dose: 5g creatine monohydrate daily as baseline (decades of safety data). Optional cognitive loading: 20g/day for 7 days, then 10g/day maintenance.
Form: creatine monohydrate ONLY. Every other form is more expensive and no more effective.
Tier 2 — Conditional (Context-Dependent)
Matter for specific populations or situations but aren't universal.
Vitamin B12 (Methylcobalamin)
Critical for Vegans/VegetariansWho needs it: Vegans (20–86% deficient per meta-analysis), vegetarians (10–40%), older adults, anyone on metformin or long-term PPIs. B12 deficiency causes irreversible neurological damage — myelin degeneration, peripheral neuropathy, cognitive impairment — and damage can be silent for years before symptoms appear.
Form matters: Methylcobalamin is the bioactive form (already methylated — no conversion needed). Cyanocobalamin is cheaper but requires conversion and contains a cyanide molecule that must be detoxified.
Dose: 1,000–2,000 mcg methylcobalamin, sublingual, daily or every other day. High dose compensates for the ~1% passive absorption rate of oral B12.
Test: Serum B12 (aim >500 pg/mL, not just "normal range" >200) + methylmalonic acid (MMA). Elevated MMA = functional B12 deficiency even if serum B12 looks OK.
Iron — Test First, Don't Blindly Supplement
Overload RiskWho needs it: Menstruating women, vegetarians, endurance athletes. Vegetarians absorb non-heme iron at 2–20% vs. 15–35% for heme iron.
The absorption hack: Vitamin C increases non-heme iron absorption by 8–20x by reducing ferric to ferrous iron. Citrus, peppers, tomatoes with iron-rich foods.
Iron overload is more dangerous than mild deficiency. Excess iron is pro-oxidant and damages the liver — the opposite of what you want. Don't supplement without testing first.
Dose (if tested low): 18–27 mg elemental iron daily with vitamin C. Iron bisglycinate is best tolerated.
Test: Ferritin (aim 40–100 ng/mL for optimal, not just ">15"). Full iron panel ideal (ferritin, serum iron, TIBC, transferrin saturation).
Zinc, Choline, Iodine, Selenium, Glycine
Commonly LowZinc
Critical for T-cell immunity, wound healing, thyroid hormone production, testosterone synthesis, and taste/smell. Vegetarian diets are lower in bioavailable zinc because phytates in grains and legumes inhibit absorption.
Dose: 15–30 mg zinc picolinate or bisglycinate, with food. Balance with 2 mg copper per 30 mg zinc if supplementing long-term. Pumpkin seeds are the best vegetarian food source.
Choline
Essential for liver function (phosphatidylcholine is required for VLDL export from the liver — without it, fat accumulates → NAFLD), brain function (precursor to acetylcholine), and methylation. The USDA flagged it as a nutrient of concern for all vegetarian patterns.
The TMAO nuance: Free choline supplements can raise TMAO via gut bacterial metabolism. However, choline from eggs (as phosphatidylcholine) did NOT significantly raise TMAO in a 2021 RCT. Eggs are the ideal choline source — 2–3 eggs/day covers most of daily need.
Iodine
A structural component of T3 and T4 thyroid hormones. If you use sea salt, Himalayan salt, or kosher salt instead of iodized table salt, you're getting essentially zero iodine from that source. Dose: 150 mcg daily. Be cautious with kelp supplements — they can contain 2,000+ mcg, enough to suppress thyroid function.
Selenium
Essential for thyroid function (selenoproteins convert T4 → active T3), glutathione peroxidase activity, and immune function. The Brazil nut hack: 1–2 Brazil nuts daily provides ~70–90 mcg selenium. One of the rare cases where a single food covers the entire requirement. Dose: 100–200 mcg daily. Do not exceed 400 mcg (toxicity risk).
Glycine
Glycine is one of glutathione's three amino acids, a critical substrate for Phase II amino acid conjugation in liver detox, a building block for collagen, and it improves sleep quality by lowering core body temperature. Dose: 3–5g daily. Can be taken before bed. Pairs with NAC for the GlyNAC protocol.
Tier 3 — Targeted Optimization (Defensible Evidence for Specific Goals)
Real evidence for specific use cases, but not universal recommendations.
Supplements in General — What's Overstated Before You Go Further
The tier system is a way of organizing evidence quality, not a shopping list. Before adding anything from Tier 3 or Tier 4, the honest picture:
The tier system doesn't mean everyone needs Tier 1. Most people who eat a reasonable diet, get some sun, and aren't chronically stressed do not need every Tier 1 compound. Test first when possible — 25(OH)D, omega-3 index, RBC magnesium, B12, ferritin. Supplement the gaps, not the catalog.
Food first, always. Most supplements have significantly weaker evidence than the food-based equivalent. Broccoli sprouts beat sulforaphane capsules. Fatty fish or flax-and-algae beat most fish oil. Eggs beat choline pills. The supplement is the backup, not the intervention.
Observational vs. RCT honesty. A large fraction of supplement claims — especially around longevity, senescence, and "anti-aging" — rest on cell culture, animal data, or observational associations, not on human RCTs showing clinical outcomes. Read every study's design, not its headline.
The supplement industry is poorly regulated. Third-party testing (USP, NSF, ConsumerLab) is the minimum bar. Multiple investigations have found contaminated, underdosed, or mislabeled products on shelves — particularly in herbal and exotic categories. Brand matters.
Marketing hype frequently outruns evidence. "Activates AMPK," "supports mitochondrial biogenesis," and "longevity compound" are mechanism claims, not outcome claims. A compound can hit a pathway in a petri dish and do nothing measurable in a human.
Don't megadose. More is not more. Fat-soluble vitamins (A, D, E, K), selenium, iodine, zinc, and iron all have meaningful toxicity ceilings. Stay inside tested ranges.
Stacking is not additive. Supplements interact with each other, with medications, and with the rest of your physiology. Adding a tenth compound rarely adds a tenth of benefit — it usually adds cost and interaction risk.
The honest default: Tier 1 basics if testing shows you need them, food-first for everything else, Tier 3/4 only for specific problems you're trying to solve with specific evidence.
NAC (N-Acetyl Cysteine)
Multiple RCTs · Gold Standard for Acetaminophen OverdoseThe body's glutathione factory. Provides the rate-limiting amino acid for your master antioxidant.
Mechanism
NAC is deacetylated to cysteine — the rate-limiting amino acid for glutathione (GSH) synthesis. Glutathione is the body's master antioxidant and central to Phase II detoxification. Every toxin your liver processes draws on glutathione reserves. NAC keeps the tank full. It's also a direct free radical scavenger and a mucolytic (breaks disulfide bonds in mucus).
Evidence by Condition
| Condition | Evidence | Key Finding |
|---|---|---|
| Acetaminophen overdose | Gold standard | IV NAC is standard of care worldwide (WHO Essential Medicines) |
| NAFLD / Liver | Meta-analysis (PMC, 2024) | NAC significantly reduced ALT, AST in NAFLD patients |
| COPD / Respiratory | Meta-analysis (PubMed, 2021) | Improved lung function, reduced exacerbations |
| OCD (augmentation) | Meta-analysis (PMC, 2024) | NAC + SSRI may benefit moderate-to-severe OCD |
| Male fertility | Meta-analysis (PubMed, 2025) | Significantly improved seminal parameters |
| Aging / GlyNAC | RCT (Frontiers in Aging) | NAC + glycine improved glutathione, oxidative stress, mitochondrial function in older adults |
The Hangover Claim Is Debunked
A 2024 RCT specifically testing NAC for hangovers found it was NOT effective. NAC taken DURING or AFTER drinking may actually increase liver toxicity. Take it BEFORE drinking or the next morning — never during.
Dose: 600–1,200 mg/day, split AM/PM, empty stomach. GlyNAC protocol: NAC 1.2g + Glycine 1.2g twice daily.
Caution: NAC is a potent ROS scavenger. In specific contexts (e.g., cancer treatments that rely on oxidative stress to kill tumor cells), this could theoretically be counterproductive. Discuss with oncologist if undergoing chemotherapy or radiation.
Curcumin
PAINS Concerns, but Clinical Data ConsistentThe active compound in turmeric. The most-studied natural Nrf2 activator — with real caveats.
Mechanism — Nrf2/ARE Activation
Under normal conditions, Nrf2 is held captive in the cytoplasm by Keap1. Curcumin promotes Nrf2 dissociation via PKC-delta-mediated phosphorylation of p62. Nrf2 translocates to the nucleus and switches on protective genes including HO-1, GST, and NQO1 (a Phase II detox enzyme).
Secondary — NF-kB Suppression
Curcumin inhibits NF-kB, the master inflammation switch. Reduces IL-6, TNF-alpha, and COX-2.
The PAINS Problem — This Deserves More Than a Footnote
Curcumin is classified as a PAINS compound (Pan-Assay Interference Compound). A landmark 2017 paper in the Journal of Medicinal Chemistry — written by senior medicinal chemists from multiple institutions — called curcumin "an unstable, reactive, nonbioavailable compound."
PAINS compounds generate false positives across a wide range of biochemical assays because they physically interfere with the assay itself (fluorescence quenching, metal chelation, membrane disruption, covalent modification of readout proteins). The consequence: a large fraction of curcumin's ~15,000+ positive in vitro papers may be assay artifacts, not real biology. Curcumin has gone into hundreds of clinical trials and has not, to date, produced a single approved drug.
Plus the bioavailability problem: Unenhanced curcumin is <1% bioavailable. Plasma levels after oral dosing are typically in the nanomolar range — orders of magnitude below the concentrations used in the positive in vitro studies.
But the clinical data is partly consistent: A 2025 umbrella review found positive effects on lipid profiles, blood pressure, inflammatory markers, and liver/kidney function. The ALT/AST reduction in 2024 NAFLD meta-analyses is consistent enough to suggest something real — though much of this literature is small trials from heterogeneous sources.
What's Overstated About Curcumin
The gap between "curcumin hits Nrf2 / NF-kB / COX-2 / 14 other pathways in cell studies" and "curcumin does X in humans" is enormous. The PAINS designation is a serious scientific critique, not a minor footnote. If you take curcumin, treat it as a modest-evidence anti-inflammatory for specific uses (NAFLD, joint pain), not as a master switch for inflammation or longevity.
Be wary of "curcumin + piperine" products if you are on any medication — piperine is a broad CYP450 inhibitor and the drug interaction risk is not theoretical.
Bioavailability — The Critical Challenge
| Formulation | Bioavailability Boost | Mechanism | Cautions |
|---|---|---|---|
| Piperine (BioPerine) | ~2,000% increase | Inhibits glucuronidation enzymes | Drug interaction risk. Inhibits same enzymes that metabolize statins, blood thinners, SSRIs, immunosuppressants. |
| Liposomal | 2.4–7.8x | Lipid bilayer vesicles fuse with cell membranes | Generally safe. Good if on medications where piperine is a concern. |
| Nanoparticle | Up to ~70x | Nano-sized particles increase surface area | Highest. Newer technology, less long-term data. |
| Phytosome (Meriva) | ~29x | Curcumin bound to phosphatidylcholine | Well-studied. Clinical trials used 1–2 g/day. Good safety profile. |
Dose: 500–1,000 mg/day enhanced curcumin (phytosome or liposomal), split into two doses with fat-containing meals.
Drug interactions: Curcumin inhibits CYP3A4, CYP1A2, and CYP2D6. Consult your doctor if you take statins, SSRIs, blood pressure meds, or blood thinners.
Sulforaphane
RCT Evidence for Toxin ClearanceThe most potent natural inducer of Phase II detox enzymes. Found in broccoli sprouts.
Mechanism — Keap1/Nrf2
Sulforaphane modifies cysteine residues on Keap1, causing it to release Nrf2. Different molecular trigger than curcumin (which works via p62 phosphorylation), which is why stacking the two gives broader Nrf2 activation than either alone. Most potent known natural inducer of NQO1 and other Phase II detoxification enzymes. These convert fat-soluble toxins (EDCs from microplastics, heavy metals, pollutants) into water-soluble compounds your body can excrete.
The Landmark Study — Egner et al.
12-week RCT in 291 people in polluted Qidong, China. Broccoli sprout beverage increased urinary excretion of carcinogen benzene by 61% and acrolein by 23% vs. placebo. This is the gold-standard detox study — one of the strongest demonstrations of a supplement measurably increasing toxin elimination in humans.
Unlike curcumin, no PAINS issue. Sulforaphane has ~80% natural bioavailability from broccoli sprouts and is not a PAINS compound. A 2025 comprehensive analysis identified 84 registered clinical trials.
Sourcing Comparison
| Source | Potency | Key Consideration |
|---|---|---|
| Fresh broccoli sprouts | 50–100x more glucoraphanin than mature broccoli. 1 oz ~ 3 lbs broccoli. | Highest potency. Must chew well or blend to activate myrosinase. Best option if practical. |
| Whole sprout supplements | High — retains glucoraphanin + myrosinase | Look for whole sprout (not just extract) so myrosinase is present. |
| Glucoraphanin-only extract | Variable — depends on gut bacteria | Missing myrosinase. Conversion relies on microbiome, varies wildly. Less reliable. |
| Stabilized sulforaphane | Direct — no conversion needed | Bypasses myrosinase requirement. Check third-party testing. |
Dose: 30–60 mg sulforaphane equivalent daily, OR 1–2 oz fresh broccoli sprouts (grow your own in a mason jar in 5 days).
Quercetin
Strong for Allergies · Sex-Specific Cardiovascular ResponseFlavonoid with antioxidant, anti-inflammatory, mast cell stabilizing, and senolytic activity.
Strongest Use Case — Allergies
Quercetin stabilizes mast cells and inhibits histamine release — working upstream of antihistamines like cetirizine. A 2022 double-blind RCT found quercetin significantly improved allergic rhinitis symptoms. A 2025 systematic review & meta-analysis of 18 studies confirmed benefit beyond conventional treatment.
Connection to alcohol: Alcohol raises baseline histamine AND inhibits DAO (the enzyme that clears histamine). Removing alcohol lowers the histamine floor; quercetin raises the trigger threshold.
Sex-Specific Cardiovascular Response
A 2025 clinical trial found quercetin reduced atrial fibrillation and improved vascular health — but ONLY in men. In women, quercetin appeared to increase CRP. A significant finding the supplement industry is not discussing.
Senolytic connection: Quercetin is part of the Mayo Clinic dasatinib + quercetin senolytic combination. Connects to NAD+ & Aging via potential CD38 inhibition.
Dose: 500–1,000 mg daily, phytosomal form preferred (standard quercetin has ~2% bioavailability).
Silymarin (Milk Thistle)
Prescription Drug in GermanyLiver-specific. Prescription drug in Germany, supplement in the US.
Silymarin protects liver cells directly — stabilizes hepatocyte membranes, stimulates protein synthesis (regeneration), scavenges free radicals in liver tissue, and has anti-fibrotic activity.
| Study | Design | Result |
|---|---|---|
| 2024 Annals of Hepatology meta-analysis | 26 clinical trials, NAFLD/NASH | Improved liver damage markers, reduced liver fat |
| Fibrosis reversal RCT (PLOS One) | Double-blind, placebo-controlled | 22.4% fibrosis reduction vs. 6.0% placebo |
| Liver-related mortality meta-analysis | Clinical data | 0.53 odds ratio (47% risk reduction vs. placebo) |
European vs. American views: Silymarin is an approved prescription drug for liver disease in Germany (Legalon). In the US, it's just another supplement — same molecule, different regulatory status.
Dose: 200–400 mg silymarin daily (standardized 70–80%). Phosphatidylcholine-bound form (Siliphos) preferred for absorption.
Berberine
AMPK · Nature Medicine RCT · Serious Drug InteractionsAn alkaloid from goldenseal, barberry, and Coptis. One of the most evidence-backed natural compounds for metabolic health — often called "nature's metformin" (with caveats).
Mechanism — AMPK Activation
Berberine activates AMP-activated protein kinase (AMPK), the same metabolic master switch triggered by fasting and exercise. AMPK activation increases glucose uptake (GLUT4 translocation), enhances fatty acid oxidation, and inhibits hepatic gluconeogenesis. Mechanism involves mitochondrial complex I inhibition, raising the AMP:ATP ratio — mimicking an energy deficit without caloric restriction.
Secondary — NF-kB Suppression + Gut Microbiome
Poor systemic bioavailability (<1%) may actually be a feature. Much stays in the gut where it modulates the microbiome — increasing short-chain fatty acid producers (Akkermansia muciniphila) and reducing endotoxin producers. This gut-mediated mechanism explains a significant portion of the metabolic benefits.
Clinical Evidence — Blood Glucose & Metabolic Syndrome
| Study | Design | Key Finding | Limitation |
|---|---|---|---|
| Lan et al. 2015 (Fitoterapia) | Meta-analysis, 27 RCTs, n=2,569 | Reduced FBG comparable to metformin; HbA1c -0.6%; LDL -25 mg/dL, TG -44 mg/dL | Most trials from China; short duration |
| Yin et al. 2008 (Metabolism) | RCT, 116 T2DM, 3 months | 1 g/day lowered HbA1c 7.5% → 6.6%, FBG -25%, TG -35% | Open-label, single-center |
| Zhang et al. 2020 (Nature Medicine) Solid | RCT, 409 prediabetic, 2 years | Reduced progression to T2DM by 42% vs. placebo | GI side effects in 13% |
Social Media Hype vs. Reality
| Claim | Reality | Verdict |
|---|---|---|
| "Activates AMPK — metabolic master switch" | True in vitro / animal. Oral bioavailability <1%. Most systemic claims extrapolate from cell studies. | Half-true |
| "Nature's metformin" | Similar glucose-lowering head-to-head. But metformin has 60+ years of data across millions. | Overstated |
| "Shuts down inflammatory pathways" | Demonstrated in cultured cells. Petri dish NF-kB suppression does not equal systemic effect at <1% bioavailability. | Half-true |
| "Helps cells burn fat for energy" | AMPK does shift metabolism toward fatty acid oxidation. Human body composition evidence weak. | Plausible, weak |
| Blood glucose + lipid improvement | Multiple RCTs and meta-analyses confirm meaningful reductions. | Well-supported |
The gut paradox: Berberine is best understood as a gut-acting metabolic compound, not a systemic anti-inflammatory. With <1% oral bioavailability, it simply does not reach most tissues at meaningful concentrations. The longevity-influencer framing of berberine as a "systemic AMPK activator that mimics exercise" overpromises — the AMPK activation seen in cultured cells is happening at concentrations roughly 100–1,000x higher than what your tissues actually see after an oral dose. The real mechanism is almost certainly gut-centered: microbiome modulation, bile acid effects, gut-liver axis signaling. That's not a bad thing — it's just a different thing than the hype claims.
What's Overstated About Berberine
The "nature's metformin" framing is catchy but oversold. Yes, multiple RCTs (including the 2020 Nature Medicine trial) show real glucose and lipid improvements. But:
• Metformin has 60+ years of safety data across hundreds of millions of patient-years; berberine has a few dozen RCTs mostly from a single region and mostly short-duration.
• Metformin has a consistent molecular mechanism; berberine's systemic effects are extrapolated from cell culture at concentrations that don't exist in human plasma.
• Metformin is dirt-cheap and well-regulated; berberine has the usual supplement quality variability.
The prediabetes RCT is a real signal. The "AMPK activator = exercise in a pill" claim is marketing. And the CYP450 interaction profile is serious — berberine is one of the few supplements that can genuinely put someone in the hospital when combined with the wrong prescription drug.
Dose: 500 mg, 2–3x/day (total 1,000–1,500 mg/day) with meals. Start low (500 mg/day) and titrate — GI side effects in ~10–15%.
Serious Drug Interaction Risk — CYP450 Inhibition
Berberine potently inhibits CYP2D6, CYP2C9, and CYP3A4. Can dangerously increase blood levels of: statins (rhabdomyolysis risk), blood thinners (warfarin — bleeding risk), antidepressants (SSRIs, SNRIs), immunosuppressants (cyclosporine, tacrolimus), macrolide antibiotics.
Hypoglycemia risk: If combined with metformin, sulfonylureas, or insulin, berberine can push blood sugar too low.
If you take any prescription medication, check CYP interactions before adding berberine.
Tier 4 — Speculative / Experimental / Skip
Weak evidence, hype, known issues, or situational use only.
Resveratrol — Skip
Lab Artifact · $720M Failure · No Human OutcomesThe short version: The foundational claim was wrong, a Fortune 500 pharmaceutical company paid $720 million based on the wrong result, shut the whole program down a few years later, and the compound has never produced a human clinical outcome that justifies taking it.
The Longer Version
The core SIRT1 activation claim was a lab artifact — the fluorescent tag used in the original assay physically interacted with resveratrol, generating a false positive. When the tag was removed and the assay redone, the SIRT1 activation signal disappeared. This was not a minor replication failure: it was the entire reason resveratrol became famous.
The Sirtris / GSK Failure
GlaxoSmithKline acquired Sirtris Pharmaceuticals in 2008 for $720 million specifically to develop resveratrol-derived drugs. By 2013, GSK shut down the entire Sirtris program after its lead compounds failed to show meaningful clinical effects. The company took massive writedowns. That $720M valuation was built on an assay artifact — and it took one of the world's largest pharma companies, with full access to internal data, five years to confirm what independent labs had already been saying.
The NIA Interventions Testing Program — the gold-standard, multi-site mouse longevity program — found no lifespan extension with resveratrol across multiple trials. Oral bioavailability is near-zero (<5 ng/mL in plasma); resveratrol is rapidly glucuronidated and cleared. A 2024 review concluded: "no conclusive clinical evidence to advocate its recommendation in any healthcare setting."
What's Overstated About Resveratrol
Essentially all of it. The "longevity molecule" framing is marketing built on a discredited assay. If a compound with this much funding, this much attention, and this many trials had a real effect, we would have seen it by now.
Every dollar spent on resveratrol would be better spent on sulforaphane, NAC, silymarin, or simply a Mediterranean diet with red wine in moderation. If you already have bottles on the shelf, use them up and don't buy more.
NMN / NR — See NAD+ & Aging
Mixed Evidence · Expensive · COIMixed human evidence, expensive, significant conflicts of interest (the Sinclair and Sirtris pattern repeating with NMN). The mechanism is real — boosting NAD+ precursors — but the outcome data in humans is weaker than the hype.
See the full NAD+ & Aging article for the detailed breakdown of NMN vs. NR, dosing, and whether it's worth it over lifestyle interventions.
Calcium D-Glucarate, Chitosan, GI Binders
Situational / ExperimentalCalcium D-Glucarate
Mechanism is sound: Inhibits beta-glucuronidase, a bacterial enzyme in the gut that reverses Phase II glucuronidation and causes toxins your liver already cleared to be reabsorbed. The biochemistry is solid.
Human data is weak: As Memorial Sloan Kettering notes, there are no robust human clinical trials. The mechanism predicts it should work for recirculation reduction; we just don't have outcome data. Dose (if trying): 200–500 mg daily with meals.
Chitosan (Microplastic Binder)
Chitosan is a positively-charged biopolymer that binds negatively-charged microplastic particles in the gut. A 2025 rat study showed >100% MP excretion (meaning it pulled out previously stored MPs from tissue). A 2025 human pilot (n=10) showed a 47% increase in MP excretion.
Caveats: Binds indiscriminately — medications, nutrients, and toxins alike. Cycle 5 days on / 2 days off. Take 2+ hours from all vitamins and medications. Dose: 1–3g daily during "on" periods, 30 min before meals.
GI Binders (Activated Charcoal, Zeolite, Bentonite Clay)
Situational, not daily. Bind everything including nutrients and medications. Keep on hand for acute exposures (food poisoning, suspected toxin exposure). Always take 2+ hours away from medications, vitamins, and food. Not a daily supplement.
Synergies & How They Stack
| Pathway | Which Compounds | Why It Matters |
|---|---|---|
| Nrf2/ARE activation | Curcumin (p62) + Sulforaphane (Keap1) | Two different molecular triggers for the same master switch = broader activation |
| Glutathione production | NAC (cysteine) + Glycine + Nrf2 activators | NAC supplies raw material; glycine completes the tripeptide; curcumin/sulforaphane increase the enzymes that use it |
| NF-kB suppression | Curcumin + Berberine (in gut) | Both suppress master inflammation switch through complementary mechanisms |
| Phase II detox enzymes | Sulforaphane (most potent) + Curcumin | Increases liver capacity to convert and excrete fat-soluble toxins |
| AMPK / metabolic sensing | Berberine (gut-mediated) | Complements fasting and exercise — but acts primarily through gut-liver axis |
| Oxidative stress defense | NAC + Omega-3 + Sulforaphane + Curcumin | Each provides antioxidant coverage through a different mechanism |
| Bone/arterial calcium | D3 + K2 | D3 absorbs calcium; K2 directs it to bones not arteries |
One nuance on NAC timing: Because NAC is a potent ROS scavenger, it can theoretically reduce some oxidative-stress-dependent signaling that curcumin and sulforaphane use to trigger protective adaptations (hormesis). In practice, at supplemental doses this is unlikely to be meaningful. But if you want to be precise: take NAC at a different time of day from morning Nrf2 activators.
Drug Interactions — Important
Supplements are not risk-free. The interactions below are well-documented and real.
| Supplement | Interaction | Affected Drugs | Risk |
|---|---|---|---|
| Berberine | Potent CYP2D6, CYP2C9, CYP3A4 inhibition | Statins, warfarin, SSRIs/SNRIs, cyclosporine, tacrolimus, macrolides | Rhabdomyolysis, bleeding, serotonin syndrome, immunosuppressant toxicity |
| Berberine | Additive hypoglycemia | Metformin, sulfonylureas, insulin | Severe low blood sugar |
| Curcumin (piperine) | Inhibits glucuronidation + CYP3A4/1A2/2D6 | Statins, blood thinners, immunosuppressants, antidepressants | Elevated drug levels, bleeding risk |
| NAC | ROS scavenging | Certain chemo agents (oxidative-stress dependent) | May reduce anticancer efficacy — check with oncologist |
| Resveratrol | Antiplatelet activity | Warfarin, DOACs, NSAIDs | Bleeding risk. Avoid high doses 1–2 weeks pre-surgery |
| K2 | Vitamin K dependent | Warfarin | Reduces warfarin effect. Coordinate with prescriber |
| Iron | Binding | Thyroid meds, antibiotics, calcium | Reduced drug absorption — separate by 4h |
| Chitosan / GI binders | Indiscriminate binding | All oral medications, all fat-soluble vitamins | Take 2+ hours from any oral drug or nutrient |
Before starting any supplement protocol: If you take prescription medications — especially blood thinners, statins, immunosuppressants, antidepressants, or diabetes medications — review interactions with your prescriber.
A Practical Daily Protocol
Informational, not medical advice. Assumes Tier 1 is in place.
| Timing | Compound | Dose Range | Notes |
|---|---|---|---|
| Morning with breakfast | Omega-3 (algae) | 500–2,000 mg EPA+DHA | With fat-containing meal |
| Morning with breakfast | Vitamin D3 + K2 | 2,000–5,000 IU D3 + 100–200 mcg MK-7 | Take together with fat |
| Morning with breakfast | Curcumin (enhanced) | 500–1,000 mg | Liposomal/phytosome if on meds; piperine otherwise |
| Morning or midday | Sulforaphane | 30–60 mg or 1–2 oz sprouts | Chew thoroughly or blend |
| Morning | B12 (sublingual) | 1,000–2,000 mcg | Methylcobalamin. Daily or every other day |
| Morning | Creatine monohydrate | 5g | Any time. Monohydrate only |
| With lunch | Zinc | 15–30 mg | With food. Balance with copper if long-term |
| Lunch & dinner | Berberine (if using) | 500 mg per meal | With carb-containing meals. Check CYP450 interactions |
| Afternoon / evening | NAC | 600–1,200 mg | Split dose. Optional GlyNAC: + 1.2g glycine |
| Evening / bedtime | Magnesium glycinate / threonate | 200–400 mg | Calming effect, supports sleep |
| Bedtime (optional) | Glycine | 3–5g | Lowers core body temp, improves sleep |
What to Test — Annual Blood Panel
| Test | What It Tells You | Optimal Range |
|---|---|---|
| Serum B12 + MMA | B12 status | B12 >500 pg/mL; MMA <0.4 umol/L |
| 25(OH)D | Vitamin D status | 40–60 ng/mL |
| Omega-3 Index | EPA+DHA tissue levels | 8–12% |
| RBC Magnesium | Intracellular magnesium | 5.5–6.5 mg/dL |
| Ferritin + iron panel | Iron stores | Ferritin 40–100 ng/mL |
| Zinc (plasma) | Zinc status | 80–120 mcg/dL |
| Selenium (plasma) | Selenium status | 100–150 ng/mL |
| TSH + Free T3/T4 | Thyroid function | TSH 0.5–2.5 mIU/L (functional) |
| Homocysteine | Methylation efficiency | <7 umol/L |
| ALT, AST, GGT | Liver function | Within reference |
Special Topic — MDMA Harm Reduction
Theoretical supplement protocol based on animal data, mechanistic reasoning, and harm reduction community knowledge. Nearly all evidence comes from animal models — human RCTs on MDMA neuroprotection don't exist for obvious ethical and legal reasons.
The neurotoxicity cascade: MDMA metabolites (not MDMA itself) drive neurotoxicity through oxidative stress in serotonergic neurons. Hyperthermia is a major multiplier — animal studies show neurotoxicity is substantially reduced or eliminated when core body temperature is kept normal. Temperature management may matter more than any supplement stack.
Strongest Animal Evidence
| Compound | Finding | Dose |
|---|---|---|
| Alpha-Lipoic Acid (R-ALA) | Fully prevented MDMA serotonergic deficits in rats at 100 mg/kg | 200–600 mg R-ALA |
| NAC | Reduced neurotoxicity + prevented hyperthermia in rats | 600–1,200 mg |
| ALCAR | Spared serotonergic + mitochondrial damage | 500–1,000 mg |
| Vitamin C | Conserved mitochondrial function | 1,000 mg |
Critical Safety Warnings
5-HTP: Minimum 48 hours AFTER last MDMA dose. Never before or during — serotonin syndrome risk.
Grapefruit / CYP2D6 inhibitors: DO NOT USE. Extends MDMA effects unpredictably and dangerously.
Spacing: Minimum 1–3 months between exposures for serotonergic recovery.
Hyperthermia: The single biggest risk factor. Stay cool, stay hydrated, rest frequently.
My Protocol
[ Jeff's Stack ]Omega-3: 2 softgels morning
Vegan D3: 1 capsule morning
Vitamin K2: 1 capsule morning
Creatine: 5g morning
Psyllium Fiber: sprinkle in smoothie
Naked Protein: 20g in smoothie
Magnesium Glycinate: evening (currently out of stock)
Magnesium Threonate: evening (currently out of stock)