Why Are My Shrooms Getting Weaker? (Magic Mushroom Tolerance Calculator)

The more often you take magic mushrooms, the weaker the effects become.

This is because of a concept called tolerance.

By Justin Cooke Last Updated: January 12, 2024
Last Updated: January 12, 2024

Tolerance formation is a problem with many substances — not just psychedelics. The body can become tolerant to the effects of caffeine, medications, and even some supplements.

Learn how to avoid tolerance to magic mushrooms, how to adapt your dose to account for tolerance, and why tolerance breaks are so important.

What is Tolerance?

Tolerance refers to the body’s innate ability to resist the effects of a psychoactive drug or substance. The body makes changes to reduce the effects of the mushrooms (or other substances) to offset their effects.

Tolerance is the reason why people who take medications every day need to increase their dosage over time. It’s common with medications such as antidepressants, anti-anxiety medications, ADHD medications, and painkillers.

Related: What is LSD Tolerance?

How Long Does It Take To Become Tolerant to Magic Mushrooms?

When it comes to magic mushrooms, tolerance formation happens fast — just one dose is enough to cause noticeable changes in effects.

If you take a 3-gram dose of magic mushrooms today and 3 more grams tomorrow — the second dose is only going to be about half as strong as the first. You’ll need a higher dose to feel the same intensity of effects.

If you take the same dose of magic mushrooms every day for a week — by the end of the week, you won’t feel anything at all.

How Long Does Tolerance Last?

Fortunately, tolerance is reversed just as quickly as it forms. If you stop taking magic mushrooms for a few days, then take it again, you’ll feel nearly the same intensity of effects as the first dose.

Within 14 days of taking a dose of magic mushrooms, tolerance formation will be entirely reversed.

Magic Mushrooms Tolerance Calculator

If you’ve used magic mushrooms within the last 2 weeks, there will likely be some tolerance to account for. If you want to take shrooms again within this window, you’ll need to take a higher dose to account for the effects of tolerance.

The calculation for determining how much magic mushrooms you need is pretty complicated, so we’ve made this shroom (and LSD) tolerance calculator to make it super simple.

Enter the last dose you used (in grams of dried magic mushrooms), the number of days since your last dose, and the desired dosage equivalent you’d like to take.

The calculator will spit out the equivalent dose you need to take to experience the same intensity of effects.

Keep in mind this is an estimate; everybody is different. This calculator is only intended to serve as a starting point to give you an idea about how the dose is likely to change because of tolerance.

Your Calculated Dose
To feel the same as your desired dose, you would need to take g

This calculator is only able to provide an estimate. Please do not be deceived by the apparent precision of the numbers. For the best experience, let 2 weeks pass between each trip, tolerance should be back to normal after 14 days.

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Guide To Tolerance Breaks

The best way to reverse tolerance to magic mushrooms is to take what’s called a tolerance break.

The idea is to simply take scheduled time away from magic mushrooms to allow the body to reverse the effects of tolerance.

Most people don’t take psychoactive doses of magic mushrooms, so tolerance breaks happen organically. Aim to space your psilocybin sessions out by at least 2 weeks.

The main reason people need to take tolerance breaks is if they’re microdosing magic mushrooms.

Depending on the microdosing protocol, you may be taking mushrooms every day, every other day, or once every 3 or 4 days.

If you’re taking mushrooms every day, even as a microdose, the effectiveness will gradually start to decline.

The standard microdosing protocol introduced by Dr. James Fadiman involves taking a microdose on the first day, followed by three days without. These non-dosing days essentially offer the tolerance breaks that are needed for the mushrooms to continue working.

If you’re microdosing daily, you should plan to take a tolerance break once every month for at least a week to maximize effectiveness.

Magic Mushroom Cross-Tolerance

Cross-tolerance happens with substances that share a similar mechanism of action [1]. When you become resistant to substance A, the changes caused by the body result in tolerance to substance B as well.

With magic mushrooms, cross-tolerance can happen to other psychedelics that work through the same 5HT receptors too. This includes LSD (and other lysergamides), mescaline (and other phenethylamines), 2C-X substances, DOX substances, 4-AcO-DMT (prodrug for psilocin), and MDMA [2,3].

If you take magic mushrooms today and LSD tomorrow, the LSD will be weaker. The same happens in reverse — taking LSD followed by magic mushrooms will result in a weaker mushroom trip.

Some cross-tolerance is theoretically possible with DMT, but studies have shown this compound is somehow exempt from the formation of tolerance.

Atypical psychedelics like salvia, ketamine, or PCP won’t result in cross-tolerance with magic mushrooms. But you can become tolerant to each of them individually with repeated use.

Cross-Tolerance With Different Magic Mushroom Species

Tolerance formation comes down to the psilocybin and psilocin content of magic mushrooms, so even if you take different species of magic mushrooms, you’re going to feel a weaker effect.

If you took a species of Panaeolus one day and a species of Psilocybe the next, tolerance would be exactly the same.

With that said, different species of magic mushrooms contain differing concentrations of psilocybin/psilocin — so the amount you’ll need to take will vary.

The most common species people take are Psilocybe cubensis. These contain roughly 0.6% 0.6% psilocybin and psilocin, respectively (dried).

Other species have more, such as Psilocybe azurescens (1.8% & 0.4%) or Psilocybe bohemica (1.3% & 0.1%); others have less such as Psilocybe liniformans (0.2% & 0%), or Psilocybe cyanofibrillosa (0.2% & 0.04%).

Keep in mind the concentration of actives in each sample of mushrooms can be widely different based on growing conditions, storage duration, and more.

What Causes Tolerance to Magic Mushrooms?

The active ingredient in magic mushrooms is a compound called psilocin. Mushrooms also contain a similar compound called psilocybin, but this molecule is converted to the active form, psilocin, by the liver.

Psilocin looks a lot like serotonin and will bind to the same receptors. The psychedelic effects are the result of psilocin binding to a particular type of serotonin receptor called 5HT2A.

After we trip on magic mushrooms, the body makes changes to this receptor to offset the psychedelic effects.

There are two ways the body may go about resisting the effects of magic mushrooms:

  1. Some of the receptors are physically blocked or hidden
  2. The receptor structure is altered to become desensitized to the effects of psilocin

Researchers still aren’t sure exactly what changes the body makes that results in tolerance, so these are currently just theories. There are known examples of both mechanisms with other substances that are much more widely studied — such as opiates and benzodiazepines (substances with a high affinity for causing tolerance).

Key Takeaways: Magic Mushroom Tolerance

Tolerance to psychedelics is surprisingly common and happens quickly. Just one dose of magic mushrooms causes noticeable differences in effects when the same dose is taken for a second time. It takes just one week to become completely tolerant (no effects).

The only way to continue feeling the effects of magic mushrooms is to take larger doses or take a tolerance break to reverse the effects of tolerance.

If you’ve used magic mushrooms within the last week and plan to take them again, check out our shroom tolerance calculator to find what dose you’ll need to take to counteract these effects.


  1. Isbell, H., Wolbach, A. B., Wikler, A., & Miner, E. J. (1961). Cross tolerance between LSD and psilocybin. Psychopharmacologia, 2(3), 147-159.
  2. LE, H. (1961). Clinical, biochemical, and psychologic effects of psilocybin. Archives internationales de pharmacodynamie et de therapie, 130, 42-52.
  3. Appel, J. B., & Freedman, D. X. (1968). Tolerance and cross-tolerance among psychotomimetic drugs. Psychopharmacologia, 13(3), 267-274.
  4. Beck, O., Helander, A., Karlson-Stiber, C., & Stephansson, N. (1998). Presence of phenylethylamine in hallucinogenic Psilocybe mushroom: possible role in adverse reactions. Journal of analytical toxicology, 22(1), 45-49.