Rapamycin use in under 25s

Is there an argument to be had for use of Rapamycin for long-term aging-delaying purposes in those under 25? For example, 18?

I understand that Alex Chen is one of the few that has written that this age-cohort could benefit.

I presume differences in dosage based on age should be considered.

When weighing waiting until ~25, or a couple years after that, I think it is important to think about the idea of the earlier the better (in terms of prevention). There is a limit to this, presumably. And that has been set by some at about 25, due to development of the brain, etc. I’m aware that in animal studies, it led to a permanent smaller size in general (body, organs). After one has finished growing in height etc however…

A question is, could proper dosage simply only draw out this developmental process for under 25s (and over 18)? Or instead could it markedly impact development and function in the long term to the downside (in terms of brain function, IQ maybe)? A quick search shows fluid intelligence peaks at 20, though I have not looked extensively into this - I am certainly not sure of the significance of that in this context.

Could that risk be weighed against any hope that starting at 18-24 has a greater impact on longevity than starting even 5 years later?

I have only just discovered Rapamycin and its applicability to longevity (in the last 2-3 days or so). I’m just curious if there could be any strong argument of starting before 25 (but after ~18). There are unknowns and risks, and some things will be theoretical or assumptions, but it seems the complete unknowns tend to somewhat be overstated by some.

For me, a desire to begin Rapamycin may be premature. I am uncertain if there is a consensus that beginning at that age is unwise (that is based on specific reasons rather than generalizations). Naturally, for this age group, the dominant tendency is to give greater weight to the potential unknowns and risks associated with the use of Rapamycin compared to its potential benefits.

Thanks in advance for any thoughts.


I would wait until 25 for anything ‘biohacking’ related, except the most safe supplements and that’s above 18. The brain is more developed at 25 and a person has more life experience. Rapamycin doesn’t have to necessarily be super harmful earlier, just that I wouldn’t trust my own decision making process at that age (in hindsight). If think you will forget about rapamycin at 25, or not find this field interesting anymore, maybe it might be worth it to think differently than I am suggesting. But I don’t know the safety of rapamycin between 18-25, someone else can fill in.

Focusing on the other healthspan longevity interventions, like diet (apoB / LDL cholesterol concentration), exercise (permanent increase in bone density with weightlifting before 25), and building habits around this is probably better. Cardiovascular exercise is important too. Rapamycin won’t take one all the way.


Indeed. I am trying to optimize in all other respects. Definitely before starting any supplements like Rapamycin.

Current info:

Background - distance runner past 5 years

18 Male, 6’ 6” 178 lbs (~20.5 BMI)

~10% body fat, ~84 lbs skeletal muscle mass (seca)

~130-150 minutes cardio/running/week primarily Zone-2 — ~125-144 HR (6 days a week). Occasional sprinting or LT + “Vo2” level (once every 8-10 days).

~100 minutes resistance training/week (Tonal Gym + dumbbells + calisthenics) — 4-5 days/week

-Supplements: Vitamin D, standard multi-vitamin.

-Diet: Decent - have started to improve it over the past two weeks. More vegetables, legumes; less bad-processed food, less sugar. Usually don’t eat until 12 PM anyways, but will start 19-5 fast or something around there, and see how that feels. Will try to cut out all food that could be bad.

For weight, will probably settle at about 185-195 lbs in the foreseeable future.


I take rapamycin infrequently, but I would not think it has much merit for people under 25 and I am 62.


You have to look at the marginal potential benefit, and the marginal potential costs / risks of taking rapamycin under age 25. There is not much evidence that taking rapamycin under the age of 25 will provide much benefit as you are likely still growing and developing. At the same time, there are risks and potential side effects for people under 25 taking rapamycin.

Its still early in rapamycin longevity research and I haven’t seen anyone ever suggesting that it would be a good idea for people under the age of 25 to take rapamycin. Given the current information we have, I don’t think there is much of a case to be made for taking rapamycin this young.


Yes, I have grown about 0.35” in the last 4 months (tends to be an annual rate of an inch for the last couple of years).

1 Like