Longevity interventions, weighed by the evidence.
NAD⁺ precursors, senolytics, mitochondrial peptides, and the wider healthspan toolkit. We grade interventions by the strength of their human data, not the confidence of their marketing.
Sexual health
Erectile-dysfunction treatments and the evidence behind them — from the proven PDE5 inhibitors to centrally acting and botanical options.
Apomorphine for ED: How It Works and What the Evidence Shows
A centrally-acting dopamine agonist that starts the erectile signal in the brain — its modest trial record, its withdrawn European approval, and why it still turns up in compounded telehealth combos.
Icariin and Horny Goat Weed: What the Evidence Actually Shows
A real PDE5 inhibitor in the test tube with coherent animal data — but weak potency, poor oral absorption, and essentially no rigorous human trials behind the “natural Viagra” label.
Gonadorelin vs hCG: Testosterone, Fertility, and Libido on TRT
Both keep the testicular axis on during TRT — but hCG mimics LH directly at the testis with real fertility data, while gonadorelin's once-daily bolus dosing fights the pulsatile pharmacology GnRH depends on.
Enclomiphene, Libido, and Erectile Function: What to Expect
Enclomiphene raises your own testosterone — so it can lift libido and erections, but only when low testosterone was the cause, not for normal-T men or vascular and psychogenic ED.
Testosterone & hormones
Testosterone therapy and the fertility-sparing alternative — the full evidence base, from TRT to enclomiphene.
TRT: what testosterone therapy is actually proven to do
An FDA-approved therapy for diagnosed hypogonadism — with real but moderate benefits (sexual function, mood; not vitality), cardiovascular non-inferiority in TRAVERSE, and a real fertility trade-off.
TRT side effects: the real risks, and the monitoring that manages them
Testosterone therapy reliably thickens the blood (most with injections), suppresses fertility, and — per TRAVERSE — raised atrial fibrillation, clots and kidney injury. Here's what monitoring catches.
TRT and Hematocrit: Why Testosterone Thickens the Blood, and What to Do About It
Erythrocytosis is the most common lab change on testosterone therapy — predictable, route-dependent, and manageable with monitoring.
Testosterone levels by age: the real reference ranges, honestly explained
There’s no official per-decade chart — labs use one adult reference range (harmonized to roughly 264–916 ng/dL in healthy young men). Levels do fall ~1%/year with age, but partly because of weight, not age alone — and a number is never a diagnosis.
TRT before and after: a realistic timeline of what testosterone therapy actually changes
For men with diagnosed low testosterone, the real “before and after” is a timeline: libido and mood early, modest body-composition change over months, energy the wildcard. Here’s what the trials show — and what the transformation photos leave out.
How to get TRT online: the diagnosis pathway, and the red flags
TRT is prescription-only and needs a real diagnosis — symptoms plus low testosterone on two morning labs. Here's the legitimate telehealth flow, and why 'prescribed from a questionnaire' is the warning sign.
TRT cost: insurance copay vs cash telehealth, and what drives the price
TRT for diagnosed hypogonadism is often insurance-covered and the drug is cheap; cash all-inclusive telehealth runs $99–$225/month. Injections are cheapest — and you may be overpaying for a covered drug.
Low testosterone treatment: the stepwise options that actually work
Confirm it's real, fix any reversible cause (weight, sleep, medications) first, then choose the medication — TRT for confirmed hypogonadism, enclomiphene or hCG when fertility matters.
TRT vs natural testosterone: what actually works?
Losing excess weight and fixing short sleep genuinely raise testosterone; exercise helps mostly via fat loss; zinc and vitamin D only if you're deficient; and most 'boosters' don't work. When that isn't enough, TRT is.
Anastrozole for Men: Does Blocking Estrogen Actually Help?
An aromatase inhibitor reliably raises testosterone and lowers estradiol in men — but routine use, especially on TRT, is off-label and risks the bone health estradiol protects.
Foods That Increase Testosterone: What the Evidence Actually Supports
Diet raises testosterone mainly by fixing a deficiency or reversing obesity — most “testosterone food” claims are hype.
Testosterone Therapy for Women: What the Evidence Actually Supports
Low-dose transdermal testosterone helps postmenopausal HSDD — and almost nothing else the marketing promises.
Boron: What the Evidence Actually Shows About the “Testosterone Mineral”
A trace mineral that nudges free testosterone and estradiol in tiny short studies — with no evidence it builds muscle or treats low T.
Shilajit benefits: a few small studies, and a real purity problem
Shilajit is a mineral-rich mountain resin marketed heavily for men. One small trial reported higher testosterone in healthy men and another better sperm quality — but the evidence is small and short, and unpurified shilajit can carry lead, arsenic and mercury.
Enclomiphene: the evidence for restoring testosterone without replacing it
Randomized trials, including two Phase III RCTs, show enclomiphene restores a man's own testosterone while preserving fertility — but it was never FDA-approved.
Enclomiphene vs TRT: same testosterone, opposite effect on fertility
Both raise testosterone — enclomiphene by stimulating the body's own production, TRT by replacing it. In trials they reached comparable levels; only TRT suppresses fertility.
Enclomiphene vs clomid: is the purified isomer worth it?
Enclomiphene is clomiphene's isolated active half. It doesn't raise testosterone more — clomiphene did, on average — but it's cleaner on estradiol and side effects.
Enclomiphene dosage: what the trials actually used
Studied as a once-daily oral dose of 6.25 to 25 mg, with 25 mg reaching testosterone comparable to a gel — but there's no FDA-approved schedule, and the product is compounded.
Enclomiphene side effects: what the trials actually found
Generally well tolerated, with fewer adverse events than clomiphene and no effect on thyroid, cortisol, lipids or bone — but the trials were small and short, and the product is compounded.
How to get enclomiphene: the legitimate route, and the trap to avoid
No FDA-approved product means it reaches men through an off-label prescription and a compounding pharmacy. Here's the legitimate path — and why gray-market 'research' sellers aren't a shortcut.
Gonadorelin: real GnRH with a proven pump role — and an unproven TRT-adjunct pitch
Gonadorelin is authentic synthetic GnRH with a legitimate diagnostic and pulsatile-pump fertility role — but the modern once-daily bolus use as an hCG substitute on TRT ignores the rhythm the evidence depends on.
Cellular energy & mitochondria
NAD⁺, mitophagy, and the mitochondrial-health compounds — where the human data is strongest.
NAD+ precursors (NR and NMN): what the human trials actually show
They raise NAD+ and look safe short-term — but human evidence is surrogate-marker level, and no trial shows they extend healthspan.
NAD+ IV therapy: an expensive drip ahead of its evidence
Clinics sell NAD+ infusions for anti-aging, energy and addiction at $250–$1,500 a session — but there's no controlled trial of IV NAD+, and the real human evidence is for oral precursors, not the drip.
NAD injections: how to get them near you or online, and what the evidence really says
Subcutaneous NAD+ injections are sold as a cheaper, at-home alternative to the IV drip — via “near me” clinics or telehealth shipped to your door. They’re compounded, not FDA-approved, and have no outcome trials; oral NR/NMN precursors are the route with the human data.
NAD therapy cost in 2026: IV vs. injection vs. oral, and what your money buys
NAD+ is priced by delivery format — IV infusions run a few hundred dollars a session, injections ~$200–$340/month, oral precursors from ~$44/month. The catch: cost runs inverse to evidence. Here’s the honest breakdown.
NMN cost in 2026: price per gram, best value, and the regulatory cloud to know about
Oral NMN runs ~$30–$70/month at common doses — but the metric that compares brands is cost per gram, and there’s a U.S. regulatory question hanging over NMN’s supplement status. Here’s the honest, evidence-anchored breakdown.
Glutathione cost in 2026: IV drip vs. injection vs. oral, and what your money buys
Glutathione is priced by delivery route — IV “gluta drips” run $150–$300+ a session, IM injections ~$100–$250/month, oral capsules under ~$30/month. The catch: cost runs inverse to evidence. Here’s the honest breakdown.
Urolithin A (Mitopure): real trials, modest results
A mitophagy-inducing postbiotic with unusually strong RCT evidence for a supplement — that reproducibly improves muscle endurance and biomarkers while repeatedly missing its primary strength endpoints.
MOTS-c: real mitochondrial biology, absent human evidence
A genuine mitochondrial-derived peptide with interesting rodent data on metabolism and exercise — but no human outcome trials. Promising biology, not a proven therapeutic.
Humanin: the first mitochondrial-derived peptide — real biology, no human trials
Discovered in 2001 in a surviving neuron, humanin is a genuine cytoprotective mitochondrial-derived peptide whose levels fall with age — but no randomized human trial shows that taking it does anything for people.
GlyNAC: impressive trials, an unsettled replication question
Glycine + NAC restores glutathione and improved a broad sweep of aging markers in randomized human trials — but those trials are small, single-group, and the one independent attempt missed its primary endpoint.
Glutathione: the master antioxidant, and where the evidence actually is
Oral glutathione really does raise your body stores (a 6-month RCT proved it) — but the longevity and detox claims are unproven, skin-lightening is modest, and IV glutathione is the most marketed, least evidenced route. The precursors may be the smarter bet.
Methylene blue: the longevity 'biohack' that's actually a drug
Low-dose methylene blue has a plausible mitochondrial mechanism and a real single-dose memory signal — but it's an FDA-approved drug, not a supplement, its anti-aging claims are preclinical, and it can cause fatal serotonin syndrome with antidepressants.
TUDCA: real bile-acid biology, an approved parent drug, and a failed flagship trial
TUDCA is a genuine ER-stress-calming chemical chaperone whose parent compound (UDCA/ursodiol) is an approved liver drug — but the longevity and broad supplement claims rest on mechanism and small or animal studies, and its highest-profile human program (ALS / Relyvrio) failed phase 3 and was withdrawn in 2024.
MOTS-c dosage: there is no validated human dose
MOTS-c's evidence is almost entirely preclinical — the real dosing data is mg/kg in mice, which does not convert to a human protocol. The ranges traded online are unvalidated, experimental self-dosing.
MOTS-c side effects: the human safety data simply doesn't exist
Animal studies haven't flagged overt toxicity at the doses tested — but there are no human safety trials, so MOTS-c's real side-effect profile in people is unknown, not proven safe.
Humanin dosage: why there is no validated human dose
Humanin and its potent HNG analog have been dosed only in cells and animals — there is no human dosing trial and no established human dose. In people, humanin is a biomarker you measure, not a drug you take.
SS-31 (elamipretide): an elegant mitochondrial mechanism meets a hard clinical record
A cardiolipin-binding peptide with a beautiful mechanism and a mostly disappointing trial history — including a failed myopathy trial and a narrow, confirmation-pending Barth syndrome approval. A straight read.
NAD⁺ nasal spray: the delivery format with the least direct evidence
Intranasal NAD⁺ is convenient and heavily marketed — but no controlled human trial shows the spray raises systemic or brain NAD⁺. A straight comparison with the better-studied routes.
The best NAD⁺ supplement: an evidence-first buyer's guide
The honest answer is a precursor, not a “NAD⁺” pill. How to choose an NR or NMN supplement on verifiable criteria — proven ingredient, studied dose, third-party testing, price — and where the evidence stops.
Ergothioneine: the mushroom-derived “longevity vitamin,” assessed
A diet-derived antioxidant with its own transporter and encouraging epidemiology — but no outcome trials. A straight read of what the evidence supports and where it stops.
NMN vs NR: the two leading NAD⁺ precursors, head-to-head
Both reliably raise NAD⁺ markers in humans; neither has proven longevity outcomes. A straight comparison on pathway, absorption, the human trial record, and the FDA wrinkle that decides which you can buy.
SS-31 (elamipretide) dosage: what the trials actually used
The elamipretide trials converged on 40 mg once daily, injected subcutaneously — but that is a studied dose in serious disease, not an approved dose for anti-aging or general use. The honest numbers, and why the gray-market version is risky.
Urolithin A dosage: the doses the trials actually used
The human RCTs used 500 mg or 1,000 mg once daily, oral — 1,000 mg ran through every muscle trial. You dose the finished metabolite (Mitopure) to bypass unreliable gut conversion. Well tolerated, but a supplement, not a proven strength drug.
TUDCA side effects: generally well tolerated, with real limits
In the human trials that exist, TUDCA is well tolerated — the reported effects are mild and gastrointestinal — but its parent drug UDCA at high doses had a safety signal, absorption interactions matter, and long-term human safety data are limited.
Urolithin A side effects: a clean record, but short trials
Urolithin A (Mitopure) was well tolerated across the human RCTs — adverse events comparable to placebo, no serious events, GRAS status. The honest catch is that those trials ran weeks to months, so long-term safety is unestablished.
Glutathione side effects: oral is benign, injectable skin-whitening is not
Oral glutathione is generally well tolerated. The honest safety issue is unregulated IV and injectable glutathione sold for skin-whitening — an unapproved use that regulators have warned about, tied to severe skin reactions, thyroid and kidney effects, and infection risk.
CoQ10: strong cardiac evidence, hype everywhere else
The Q-SYMBIO trial cut mortality in heart failure — but statin-muscle data are mixed, migraine support is moderate, and the anti-aging pitch rests on a decline, not an outcome.
PQQ evidence: a strong mitochondrial mechanism, thin human data
PQQ activates the PGC-1α biogenesis pathway in the lab — but the human case is a few small, short, partly industry-run trials with no healthspan outcomes.
Cognition & nootropics
The supplements sold for memory, focus and clean energy — graded by what the human trials actually show.
Gotu Kola (Centella asiatica): What the Evidence Actually Shows
Strong for venous insufficiency and topical wound healing; the cognition and longevity claims rest on thin, mixed data.
Alpha-GPC: What the Evidence Actually Shows
A cholinergic precursor with real dementia-trial data, weak ergogenic studies, and an unresolved 2021 stroke-risk signal.
Paraxanthine: The Evidence on Caffeine's Primary Metabolite
The well-characterized methylxanthine behind the “cleaner caffeine” pitch — what the small, mostly industry-funded human trials actually show.
Phosphatidylserine: Evidence for Memory, Cortisol, and Cognitive Health
A membrane phospholipid with real biology, older positive cognition data on a form you can no longer buy, and a weaker case for the soy-derived version sold today.
Cerebrolysin: what it is, and what the evidence actually shows
A porcine-brain-derived peptide mixture sold abroad for stroke and dementia — and pitched online as a nootropic. A straight read of the Cochrane reviews and the regulatory reality.
Cerebrolysin dosage: the regimens trials actually used
In the largest stroke trials the dose was 30 mL/day by IV infusion, over 10-to-21-day courses. But there's no FDA-approved dose, the pooled evidence shows no benefit on death, and it's a clinician-administered drug — not a home protocol.
Cerebrolysin side effects: well tolerated, with one serious flag
The trials rated it reasonably tolerated and the common effects are mild and infusion-related — but Cochrane flagged a possible increase in non-fatal serious adverse events, and its porcine source carries a rare anaphylaxis risk.
Lithium orotate: an intriguing population signal, almost no direct evidence
Trace lithium in drinking water tracks with lower suicide and dementia rates — but that's an association, and lithium orotate itself has essentially no controlled human trials.
Metabolic longevity
Glucose, AMPK, and the metabolic-aging hypothesis — metformin and berberine.
Metformin for longevity: TAME, MILES, and the healthspan hypothesis
A provocative survival signal, a credible mechanism, surrogate-level human data — but the definitive outcome trial hasn't reported. An honest grade.
Berberine: real evidence for blood sugar, not for weight loss
A plant alkaloid that activates AMPK and lowers glucose and LDL in human trials — with effects on blood sugar comparable to oral diabetes drugs. But it's not a GLP-1, and 'nature's Ozempic' is a myth.
Berberine vs metformin: same switch, very different evidence
Both activate AMPK, and in a small head-to-head berberine's glucose-lowering matched metformin's. But metformin is an approved drug with decades of data; berberine is a low-certainty supplement.
Berberine vs Ozempic: why 'nature's Ozempic' is a myth
Berberine and Ozempic work by completely different mechanisms — AMPK vs GLP-1 — and produce completely different results: no significant weight change for berberine versus ~15% for semaglutide.
Berberine dosage: how much, when, and the safety catches
Trials used 500 mg two to three times daily with meals — split because berberine is barely absorbed (under 1%). Plus the GI effects, drug interactions, and the firm pregnancy contraindication.
SLU-PP-332: the “exercise mimetic” that lives entirely in mice
A synthetic pan-agonist of the ERRα/β/γ receptors switches on an endurance-training program — in rodents and cell culture. A straight read of the preclinical evidence, and why there is no human story yet.
The best berberine supplement: an evidence-first buyer’s guide
No fake lab rankings — just the verifiable criteria that actually separate a good berberine supplement from a bad one: form, dose, third-party testing, manufacturing and value.
Acarbose and longevity: a carb-blocker with a real mouse-lifespan signal
An approved diabetes drug that repeatably extended lifespan in NIA mice — more in males. A straight read of the mouse data, the human gap, and the side-effect ceiling.
Senescence & aging compounds
Rapamycin, senolytics, and the longevity supplements — strong stories, varied evidence.
Rapamycin for longevity: the PEARL trial and the human evidence
Gold-standard mouse lifespan data, randomized human trials on an immune surrogate, and a one-year PEARL safety read — but no evidence yet that it extends human healthspan.
Rapamycin cost in 2026: a cheap generic drug behind an off-label access premium
Sirolimus is an off-patent generic — a month of tablets is often ~$50–$100 with a coupon. So what does rapamycin really cost for longevity? Mostly the off-label telehealth access, not the pills. The honest breakdown, anchored to the evidence.
Spermidine: a great longevity story, still waiting on the trials
A polyamine that induces autophagy, extends lifespan in mice, and tracks with lower mortality in population studies — but the association is observational, and the best human trial found no effect.
Fisetin: a powerful senolytic in mice, unproven in humans
A dietary flavonoid that's the most potent senolytic of its class and extends lifespan in mice — but the human trials that would test the senolytic claim are still ongoing, with no published outcomes.
Quercetin: one real benefit, and a reputation that outruns it
A flavonoid with modest, meta-analysis-backed blood-pressure benefit — but its 'senolytic' fame belongs to the dasatinib+quercetin combo, and its exercise and allergy claims are weak.
Resveratrol: spectacular in mice, disappointing in humans
The 'red wine longevity molecule' extended lifespan in yeast and mice via SIRT1 — but human trials show only modest benefit in diabetics, nothing in healthy people, and it even blunted exercise gains.
Taurine and aging: what the Singh 2023 Science work and the human data actually show
A robust mouse lifespan result — but 2025 human data found taurine doesn't reliably decline with age, and the only human trials are small cardiometabolic ones.
Epitalon (epithalon): the honest evidence behind the telomerase and longevity claims
Marketed for telomerase activation and life extension. The supporting science is old, small, and almost entirely from one Russian lab — and largely unreplicated.
Epitalon (epithalon) dosage: the circulated short-course schedule vs. the (missing) standard
There is no FDA-approved epitalon dose. Here’s the short-course pattern people actually circulate — the ~10–20 day cycle, the “50 mg” vial confusion — and why every number is reported, not recommended.
Epitalon side effects: what's actually known about epithalon safety
The small Russian studies call epitalon (epithalon) well tolerated — but the safety database is tiny, old and single-group, there's no long-term human data, telomerase activation raises a theoretical cancer question, and the real risk is unregulated gray-market supply. “Few reported effects” isn't “proven safe.”
Sulforaphane: real human data, in niches that aren't longevity
The broccoli-sprout Nrf2 activator has genuine randomized trials — for autism and type-2 diabetes. But its anti-aging claims are preclinical, and bioavailability depends heavily on the preparation.
Calcium AKG (Rejuvant): a real metabolite, an overstated headline
Alpha-ketoglutarate declines with age and compresses morbidity in mice — genuinely interesting. But the viral 'about 8 years younger' claim comes from an uncontrolled, industry-linked clock study, and no human trial shows a hard outcome.
Astragalus & TA-65: a real telomerase activator, an unproven anti-aging claim
Astragalus is an immune-tonic herb whose saponin cycloastragenol genuinely activates telomerase in cells — but the longevity pitch rests on small, industry-linked human studies, while the better clinical data sit in kidney and heart disease.
Spermidine dosage: the trials used about 1 mg a day
Human cognition trials used a wheat-germ extract at 0.9–1.2 mg spermidine/day — and the most rigorous one was null. Sold products run higher (~1–6 mg/day) with no dedicated trials, and there's no established anti-aging dose.
Fisetin dosage: the “hit-and-run” trial protocol vs the supplement bottle
The senolytic dose being tested in humans is a ~20 mg/kg burst for two days, repeated monthly — roughly 1400 mg on a trial day for a 70 kg adult, and nothing like the 100–500 mg/day sold OTC. It's also experimental, with no published human outcomes.
Rapamycin side effects: the approved-use profile and the longevity-dose nuance
Mouth ulcers, raised lipids and glucose, infection risk and impaired wound healing come straight from sirolimus's transplant label — but low intermittent longevity dosing looks better tolerated, if unproven long-term.
Spermidine side effects: well tolerated, and one theoretical caveat
In the human trials spermidine's adverse events ran level with placebo — mild and mostly gastrointestinal. The polyamine/cancer concern is theoretical and unproven; the concrete flags are a wheat-germ allergen and the absence of long-term data.
Fisetin side effects: well tolerated, with honest cautions
Fisetin is generally well tolerated — long dietary history, low animal toxicity, no adverse events in the one human study. The real caveats are mild GI upset at high doses, a theoretical CYP drug-interaction flag, and the unproven long-term safety of experimental senolytic doses.
Apigenin: what the evidence says about sleep, anxiety, and the NAD+ longevity claim
A plausible GABA-A mechanism and a CD38/NAD+ longevity hypothesis — but the human data are mostly from chamomile and preclinical models, not isolated apigenin.
Klotho, the longevity protein: strong biology, no supplement you can buy
Klotho suppresses aging in mice, tracks with human longevity and cognition, and boosted cognition in aged monkeys in 2023 — but it's a large protein you can't take orally.
FOXO4-DRI: an elegant senolytic peptide with zero human evidence
A rationally designed peptide that frees p53 to kill senescent cells and reversed features of aging in mice — but rests on essentially one landmark study, has no human trials, and is sold gray-market with no safety basis.
Landmark trials
The human and animal trials that anchor longevity science — what they showed, and where the evidence still falls short.
The CALERIE trial explained: what a 2-year test of caloric restriction actually showed
The landmark randomized trial of sustained caloric restriction in healthy adults moved aging biology in the right direction — but participants hit only about 12% of a 25% target, and it measured biomarkers, not lifespan.
The NIA Interventions Testing Program: the gold standard for longevity claims
How the ITP tests compounds for lifespan in genetically diverse mice across three blinded labs — what passed (rapamycin, acarbose, canagliflozin), what failed (resveratrol), and why it is the benchmark.