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how often can you do a 72 hour fast

A 72-hour fast is usually best treated as an occasional practice, not something to do back-to-back. For many healthy adults, a cautious range is a few times per year to once a month at most , while some forum users suggest once every week or two but that is more aggressive and not a medical recommendation.

Quick Scoop

A practical answer is: if you’re healthy and experienced, think “monthly or less”; if you’re new to prolonged fasting, think “quarterly or a few times a year.” Publicly available guides also caution that doing 72-hour fasts too often can raise the risk of dehydration, electrolyte problems, low blood pressure, and inadequate nutrition.

What people commonly do

  • Beginners or general wellness: about 2–4 times per year.
  • More experienced fasters: once a month or less is a common upper-limit suggestion in some guides.
  • Forum advice: some people say once every week or two , but that’s anecdotal and much more aggressive than most safety-focused guidance.

When to be more careful

You should be extra cautious or avoid repeated 72-hour fasts if you have:

  • Diabetes or take glucose-lowering medication.
  • Kidney, heart, or blood-pressure issues.
  • A history of eating disorders.
  • Pregnancy, breastfeeding, or a medical condition that affects nutrition.

Safer approach

If you still want to do it, a conservative pattern is:

  1. Start with one fast and see how you recover.
  2. Refeed gradually after the fast.
  3. Don’t repeat it if you had dizziness, weakness, palpitations, or severe fatigue.
  4. Talk to a clinician first if you take medications or have any chronic condition.

Bottom line

If you want the shortest safe answer: most people should not do a 72-hour fast more than once a month, and many should do it only a few times a year. If you want, I can also give you a safer fasting schedule based on your goal: fat loss, autophagy, or insulin control.