Treatment should be started early in life but not earlier than growth is completed (Figure 3). For example, rapamycin may be considered from the age of 21–25 (just an example). This may seem at odds with the work showing rapamycin treatment started at the age of 20 months (old mice) was as effective as treatment started at the age of 9 months [11, 14]. However, this result should not be overgeneralized, as the result may depend on specific conditions, mouse strains and doses. In fact, this was challenged by additional experiments (rapamycin plus acarbose) by the same authors [43]. Also, adaptation to rapamycin may explain the result. I suggest that an early-onset treatment in post-development with low doses that would be gradually increased to maximal anti-aging doses by the age of 50 (an arbitrary age) would be most effective.
He is suggesting that results claiming a short regime in early life being equal to lifetime regime might be due to adaptation and therefore needing a larger dose to maintain the effect.
Something that might be worth considering for anyone in their 30s or 40s taking megadoses already. Maybe you should be at lower doses now to have the “room” to increase your dose later.