Stage 2 of 4 · Small studies in people
NMN (nicotinamide mononucleotide)
Supplement
A molecule the body uses to make NAD+, which cells need to turn food into energy.
Stage 2 because there are 9 published trials and 55 registered trials in people, but no large ones yet.
AvailabilityOver-the-counter supplement
The research so far · counted from PubMed
Stage 2 of 4 · Small studies in people
Creatine
Supplement
A compound stored in muscles that supplies quick bursts of energy. The body makes some, and some comes from meat and fish.
Stage 2 because there are 62 published trials and 171 registered trials in people, but no large ones yet.
AvailabilityOver-the-counter supplement
The research so far · counted from PubMed
Stage 2 of 4 · Small studies in people
Rapamycin
Prescription
Extends lifespan in mice. Human studies so far are small.
Stage 2 because there are 25 published trials and 40 registered trials in people, but no large ones yet.
AvailabilityPrescription, used off-label for aging
The research so far · counted from PubMed
Stage 4 of 4 · Widely recommended
GLP-1 drugs
Prescription
Approved for diabetes and weight. Large trials are now looking at heart, kidney and brain aging.
Stage 4 because it is FDA-approved for chronic weight management (Wegovy and Zepbound labels).
AvailabilityPrescription
The research so far · counted from PubMed
Stage 3 of 4 · Large studies in people
Red light therapy
Device
Small trials for skin, of mixed quality.
Stage 3 because 10 large randomized trials in people for aging or skin and hair have been published.
AvailabilityClinics and home devices
The research so far · counted from PubMed
Stage 4 of 4 · Widely recommended
Metformin
Prescription
Studied for aging mostly through observational data. A large aging trial has been proposed.
Stage 4 because it is FDA-approved to lower blood sugar in type 2 diabetes.
AvailabilityPrescription, approved for diabetes
The research so far · counted from PubMed
Stage 2 of 4 · Small studies in people
Urolithin A
Supplement
A compound gut bacteria make from foods such as pomegranates, berries and walnuts. It is studied for how cells clear out worn-out energy parts.
Stage 2 because there are 32 published trials and 43 registered trials in people, but no large ones yet.
AvailabilityOver-the-counter supplement
The research so far · counted from PubMed
Stage 2 of 4 · Small studies in people
NR (nicotinamide riboside)
Supplement
A form of vitamin B3 that the body turns into NAD+, a molecule cells need for energy.
Stage 2 because there are 9 published trials and 127 registered trials in people, but no large ones yet.
AvailabilityOver-the-counter supplement
The research so far · counted from PubMed
Stage 3 of 4 · Large studies in people
Omega-3 fatty acids
Supplement
Fats found in oily fish such as salmon and sardines, and in some plant and algae oils.
Stage 3 because 22 large (phase 3) trials in people for aging, memory and mood or the heart and blood sugar have been published.
AvailabilityFood, supplements and a prescription form
The research so far · counted from PubMed
Stage 3 of 4 · Large studies in people
Vitamin D
Supplement
A vitamin the skin makes in sunlight. It also comes from some foods.
Stage 3 because 13 large (phase 3) trials in people for aging or muscles, bones and mobility have been published.
AvailabilityOver-the-counter supplement
The research so far · counted from PubMed
Stage 4 of 4 · Widely recommended
Exercise
Lifestyle
Recommended in health guidelines worldwide. Large long-term studies link it to longer, healthier lives.
Stage 4 because it is recommended in the US Physical Activity Guidelines for Americans.
AvailabilityFree, for almost everyone
The research so far · counted from PubMed
Stage 4 of 4 · Widely recommended
Minoxidil
Skin and hair
A medicine for hereditary hair loss.
Stage 4 because it is FDA-approved over the counter to regrow hair on the top of the scalp.
AvailabilityOver the counter (scalp liquid or foam)
The research so far · counted from PubMed