Ingredient Guides

Every ingredient monograph on this site: what it is, how it works, what the clinical literature actually shows, dosing forms, and safety considerations.

All ingredient guides

Resveratrol — Resveratrol is a plant polyphenol found in grape skins and red wine, and it is the compound behind the sirtuin claims that made the supplement famous. The sirtuin activation was first reported with a fluorescent tag on the test peptide. Without the tag, two papers from 2009 and 2010 found no activation, and human trials at 150 mg to 5 g a day show small, mixed effects.
Vitamin D3 (Cholecalciferol) — Vitamin D3 (cholecalciferol) is the form of vitamin D your skin naturally produces from sunlight, and it is the most effective supplemental form for raising and maintaining healthy blood levels. Most adults, especially those living above the 37th parallel, do not get enough from sun and food alone.
Ashwagandha (Withania somnifera) — Ashwagandha (Withania somnifera) is the most clinically studied adaptogenic herb, with strong evidence for reducing cortisol, improving stress resilience, enhancing sleep quality, and supporting physical performance. Used in Ayurvedic medicine for over 3,000 years, it is now backed by modern randomized controlled trials showing measurable effects on both mental and physical stress markers.
Bacopa Monnieri (Brahmi) — Bacopa monnieri is a creeping wetland herb from Ayurvedic tradition whose active saponins, the bacosides, have been tested in at least nine placebo-controlled trials for memory in healthy adults. At 300 to 320 mg a day of a standardized extract, the consistent finding is better retention of newly learned information after about 12 weeks. The catch: it does nothing in an afternoon, and the most common complaint in the trials was an unhappy stomach.
Akkermansia muciniphila — Akkermansia muciniphila is a gut bacterium that lives in your intestinal mucus layer and eats mucin, the protein that layer is made of, which sounds destructive and is closer to the opposite: it keeps the layer turning over. You almost certainly already host it, at more than one percent of the bacterial cells in your stool. The catch is that the one randomized human trial of it got its results from dead cells, not live ones.
Citicoline (CDP-Choline) — Citicoline (CDP-choline) is the molecule every cell uses one step before building phosphatidylcholine, the main fat in brain cell membranes, and it also carries a choline payload for the neurotransmitter acetylcholine. Swallowed as a capsule it is split in the gut into choline and uridine, which the brain reassembles. Trials at 250 to 500 mg a day improved attention in healthy adults and memory in older adults with age-related memory complaints, mostly in manufacturer-funded studies of four to twelve weeks.
Melatonin — Melatonin is the hormone your pineal gland releases when the light goes down, and its job is to tell the rest of the body what time it is, not to knock you out. Taken at the right time, a dose small enough to mimic your own nighttime level shortens the time it takes to fall asleep and nudges a jet-lagged body clock. The catch: the trials that proved that used 0.3 to 1 mg, and most bottles on the shelf hold 3 to 10 mg.
Trimethylglycine (TMG) — Trimethylglycine (TMG) is the same molecule as betaine. The body makes it from choline, and small amounts come from beets, spinach, cereals, and seafood. Its job is to donate methyl groups to homocysteine. The catch: the human trials in this review used grams a day, while the NMN + NR serving from Mt. Angel Vitamins lists 50 mg per serving.
Zinc — Zinc is the trace mineral that hundreds of enzymes need to do their work. The recommended intake is 8 mg a day for adult women and 11 mg for adult men, and the upper limit from all sources is 40 mg a day. The catch is copper: zinc taken at 50 mg or more for weeks can lower copper absorption, and a 2018 series of seven copper-deficient patients found that four had been using zinc-containing denture adhesive.
NMN (β-Nicotinamide Mononucleotide) — NMN (β-nicotinamide mononucleotide) is a direct precursor to NAD+, the coenzyme your cells need for energy production, DNA repair, and essentially every metabolic process that keeps you alive and functioning. Supplementing with NMN has become one of the most researched approaches to supporting healthy NAD+ levels, which decline significantly with age.
Quercetin — Quercetin is a plant flavonoid with potent antioxidant, anti-inflammatory, and natural antihistamine properties, making it one of the most versatile supplements for immune support and seasonal allergy relief. Found naturally in onions, apples, and berries, supplemental quercetin delivers concentrated doses that food alone cannot match.
Probiotics — Probiotics are live microorganisms that provide a health benefit when you take enough of them, and "enough" is measured in colony-forming units (CFU) of a specific, named strain. The human evidence is strain-specific and condition-specific: strong for a few strains in a few situations, thin for a healthy adult taking a capsule every day. The catch is that most labels never name a strain, so you cannot match the bottle to a trial.
Ellagic Acid — Ellagic acid is a plant polyphenol found in pomegranate and in related molecules called ellagitannins. Gut bacteria convert it into urolithins, and much of the human data is really about those urolithins or about pomegranate juice. The surprise is how little reaches the blood: in one 2006 study, plasma ellagic acid peaked at 0.06 µmol/L about an hour after pomegranate juice. Human trials of the isolated compound are few, and no supplement dose is established.
Magnesium — Magnesium is the mineral that about 300 enzymes need before they will run, including the ones that make ATP, relax a muscle fiber, and quiet a nerve signal. Roughly half of Americans eat less than the estimated requirement, which is why it sits in every pharmacy aisle. The catch is the form: in the one 60-day trial that compared three forms head to head, magnesium oxide, the cheapest and most common, did no better than placebo.
CoQ10 (Coenzyme Q10) — CoQ10 (coenzyme Q10) is a naturally occurring compound found in every cell in your body, where it plays an essential role in mitochondrial energy production and serves as a powerful lipid-soluble antioxidant. Your body's production of CoQ10 peaks around age 20 and declines steadily after that, making supplementation increasingly relevant as you age.
NR (Nicotinamide Riboside) — Nicotinamide riboside (NR) is a form of vitamin B3 that the body can convert into NAD+, a coenzyme used in energy metabolism and DNA repair. NMN, a closely related precursor, has its own [monograph](/ingredients/nmn-nicotinamide-mononucleotide). In human trials, NR raised NAD+ metabolites in the blood at single doses of 100 to 1,000 mg and at up to 3,000 mg a day for four weeks. Trials have measured blood NAD+ far more than anything a person would feel, and the functional results so far are small, short, or null.
Piperine (Bioperine) — Piperine is the pungent alkaloid of black pepper, and Bioperine is a trademarked black pepper extract that supplement makers use as a source of piperine. In small human studies, piperine raised blood levels of curcumin, propranolol, theophylline and phenytoin (PMIDs 9619120, 1815977, 16767797). It also interacts with prescription medicines, most clearly phenytoin, so anyone on medication should ask a clinician first. The human studies are small, and none of the ones read for this page tested piperine with NMN or NR, so the pairing is untested.
Vitamin K2 (Menaquinone) — Vitamin K2 (menaquinone) is the branch of vitamin K that activates the proteins deciding where calcium ends up: osteocalcin, which binds it into bone, and matrix Gla protein, which keeps it out of artery walls. Gut bacteria make some, fermented and animal foods carry a little, and the long-chain MK-7 form stays in the blood for days instead of hours. The catch is that spinach does not cover this job: K1 from greens goes mostly to the liver for clotting.
Urolithin A — Urolithin A is a postbiotic compound your gut bacteria make from the ellagitannins in pomegranates, walnuts, and berries, and it's the most-studied natural activator of mitophagy, your cells' system for clearing out worn-out mitochondria. The catch: most people's gut bacteria can't produce a meaningful amount, which is the entire reason direct supplementation exists.