Trametinib
Trametinib, MEK inhibitor
Written by Aaron CuhaReviewed Sep 2026
Also known as: Mekinist, GSK1120212
An approved melanoma drug that extended mouse lifespan, and did so additively with rapamycin, which suggests the two pathways are separate levers rather than the same one.
Overview
Most compounds that extend lifespan in mice are thought to work through nutrient sensing, which means adding them together should produce little more than either alone. Trametinib is interesting because it appears not to fit that pattern.
It is an approved MEK inhibitor used in melanoma, blocking the Ras and MAPK growth signalling cascade, a different pathway from mTOR. In mouse work it extended healthspan and lifespan, and when combined with rapamycin the effects were additive rather than overlapping.
That additivity is the finding worth attention. If two drugs acting on separate pathways add up, the ceiling on pharmacological lifespan extension is higher than either alone suggests. It is mouse data, it comes from a drug with serious human toxicity, and the ageing result has never been tested in a person.
Mechanism of action
A selective allosteric inhibitor of MEK1 and MEK2, the kinases immediately downstream of RAF in the Ras, RAF, MEK, ERK cascade. That cascade transmits growth factor signals to the nucleus and drives proliferation, and it is constitutively active in cancers with BRAF mutations, which is the basis of the approval. Its ageing rationale is that reduced Ras and MAPK signalling extends lifespan across model organisms, and that the pathway is distinct from mTOR nutrient sensing, which is what makes additive effects with rapamycin plausible rather than surprising.
Human evidence
A large oncology record with well-characterised and serious toxicity. No human ageing data at all.
- Approved for BRAF-mutant melanoma and other BRAF-mutant cancers, usually in combination with a BRAF inhibitor, on randomised survival data.
- Toxicity is substantial and includes cardiomyopathy with reduced ejection fraction, retinal disorders including retinal vein occlusion, serious skin toxicity, interstitial lung disease and haemorrhage.
- No human study has examined lifespan, healthspan or any ageing endpoint.
- The ageing evidence is entirely in mice.
What this does not tell you: This is an anticancer drug with organ toxicity that requires cardiac and ophthalmic monitoring in the population it is approved for. The lifespan result is in mice. The gap between a mouse lifespan finding and a safe human intervention is enormous here, larger than for metformin or rapamycin, because the toxicity is not subtle.
Reading the research record
The additivity with rapamycin is the part that advances the field, and it is worth stating precisely what it does and does not mean. It suggests Ras and MAPK signalling is a lever on ageing separate from mTOR nutrient sensing, which raises the theoretical ceiling for combination geroprotection. That is a real and interesting mouse result.
It is not an argument for taking this drug. The toxicity profile includes cardiomyopathy and retinal vein occlusion, monitored carefully in cancer patients for whom the trade-off makes sense. Nobody has established a dose that would engage the ageing mechanism without those risks, and the site's fasting and training sections contain interventions with better evidence and no toxicity at all.
The evidence, charted
Fig. 1 · evidence composition
0of 1 citation (0%) is in people
Every citation cited here is Animal work; no other study type is cited on this page. This count is of our own citation list and understates any literature larger than the sources we cite.
Fig. 2 · evidence over time
Every citation here was published in 2025.
Too few distinct publication years on this page to plot as a timeline.
Fig. 3 · legal status at a glance
US
Approved
UK
Approved
AU
Approved
CA
Approved
Approved in all four jurisdictions shown. A jurisdiction's classification is a regulatory fact, not a verdict on the science; see Legal status below for the full text and any notes.
Fig. 4 · dose response
No human dose response curve exists
We draw this figure where the data supports it. For this compound in humans it does not, so the panel stays empty rather than borrowing an animal curve and implying it transfers.
Key studies & citations
- Animal2025
The geroprotectors trametinib and rapamycin combine additively to extend mouse healthspan and lifespan
Mouse work. Trametinib extended healthspan and lifespan, and combined additively with rapamycin rather than redundantly. Additivity implies the two act through separate pathways, which matters because most candidate geroprotectors are thought to converge on nutrient sensing.
Nature Aging
Frequently asked questions
Does trametinib extend lifespan?
In mice, yes, and additively with rapamycin. In humans it has never been tested for any ageing endpoint. The combination finding is scientifically important because it suggests two independent pathways rather than one.
Why does additivity matter?
Because most candidate geroprotectors are believed to converge on nutrient sensing, which would mean stacking them buys little. Two drugs whose effects add up imply separate levers, and a higher theoretical ceiling for combining interventions.
Could a person take it for ageing?
Not sensibly. It causes cardiomyopathy, retinal disorders, serious skin toxicity and haemorrhage at its approved doses, which require cardiac and eye monitoring. No ageing-relevant dose has been established in people, and the risk is not speculative.