Fasting versus Rapamycin

I’ve asked Bard (Google LLM) about Fasting (duration) vs Rapamycin (mg/week) and got this reply:
According to Dr. Valter Longo, the following equation can be used to calculate the fasting duration required to achieve the same effect as taking rapamycin:
fasting_duration = (rapamycin_dose * 10) + 12
fasting_duration is the fasting duration in hours
rapamycin_dose is the dose of rapamycin in milligrams per week
So, to achieve the same effect as taking 5mg of rapamycin per week, you would need to fast for 62 hours.


  • I can’t find the article where Longo made this claim and Bard can’t point me (does somebody know?)
  • What do people think about fasting as a rapamycin mimic

I would not trust any AI on this. AI hallucinates and make things up. But even if it is true 6mg would same you 3 day fast, 10mg would be almost 5 days… when do you eat? One would die of starvation probably…

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I agree with @scta123 on this. It is worth trying to find out what Valter Longo actually said (if anything like this.) I do not think things like fasting are linear in effect anyway. Nor would I say Rapamycin is.

Best to start with the objective (Mitophagy/improved mitochondrial efficency) and work out what best to do to acheive this.

I am currently running a system of alternating fasting for 6 days a week (apart from parties). So if I don’t have a party to go to Mondays, Wednesdays, and Fridays are orientated towards eating not massively, then Tuesdays, Thursdays and Saturdays are mainly for fasting (although I eat a little perhaps at most 250 calories).

On Saturday which was a fasting day I also took Rapamycin (6mg at a separate and earlier time to berberine and curcumin and no grapefruit juice). The idea was to have multiple simultatenous stimulants of autophagy.

Joan mannick mentioned in an inside tracker podcast that fasting did not stimulate autophagy in older adults due to mTOR always being switched on (hypergrowth, I suppose). I wonder if she thinks any amount of rapa turns autophagy back on or if a person has to be have recently taken rapa (high in blood) to get an autophagy effect from fasting.


Here is the Joan Mannick podcast

That’s an interesting thought.

I think an issue for older people is that BECLN1 is a longer gene which is harder to get expressed for older people.

However, my own view is that it is best to get as many things as sensible/possible pointing in the right direction for what you want to happen (autophagy).

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I guess it’s complicated… I asked both BARD and CHATGPT, who said
The effects of fasting on autophagy in young and old people are not fully understood. However, some studies have shown that fasting may trigger autophagy more effectively in older people.

One study found that fasting for 24 hours increased autophagy in mice of all ages, but the increase was greater in older mice. Another study found that fasting for 7 days increased autophagy in human muscle cells, but the increase was greater in older cells.

These studies suggest that fasting may be a more effective way to trigger autophagy in older people. However, more research is needed to confirm this finding and to understand the underlying mechanisms.

Research suggests that fasting can indeed stimulate autophagy in both young and old individuals to some extent. However, there may be differences in the efficiency or effectiveness of autophagy between age groups.

  1. Young Individuals: In young, healthy individuals, autophagy is generally more efficient and active compared to older individuals. Fasting or calorie restriction can further enhance autophagic processes in young people, helping to maintain cellular health and potentially provide benefits in terms of longevity and disease prevention.
  2. Older Individuals: As people age, the efficiency of autophagy tends to decline. This reduced autophagic activity is one of the factors associated with aging-related health issues. Fasting or dietary interventions can still stimulate autophagy in older individuals, but it may not be as robust as in younger individuals. However, it’s worth noting that even a modest increase in autophagy can have potential health benefits.
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I don’t think they are the same and not a perfect substitute for each rather. Equation is interesting though, if correct, as it indicates a magnitude of the effect.

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I seriously doubt that there is any validity to that fasting formula at least in humans. No way anyone has enough data or information on how Rapa works to develop that formula.