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Mushroom dose calculator

Dried or fresh grams for an intention level, the psilocybin it roughly equals, and the doses used in research, with why potency is the biggest unknown.

Start lower than you think

The same weight of mushroom can hold several times more or less psilocybin than the last batch, and nothing on this page can tell you which you have. Start at the lowest amount shown, never redose because effects seem slow, and check every medicine you take on the interaction checker first. [The abuse potential of medical psilocybin according to the 8 factors of the Controlled Substances Act, Neuropharmacology, 2018, read 28 October 2026]

Intention level
Dried or fresh

Low, dried

0.3 g to 2 g

About 5 to 10 mg psilocybin, assuming 5 to 15 mg per dried gram.

Start with 0.3 g. That assumes strong material. Mushrooms vary several-fold in strength, and you cannot tell by looking. The higher figure is for weak material, which you cannot confirm.

A Johns Hopkins dose-effect study gave 5 and 10 mg per 70 kg as its lower doses. In a depression trial, 10 mg did not reduce scores significantly; 25 mg did.

Every level, worked out

The table repeats the calculator for every option, so you can read it without JavaScript. The cautious start assumes strong material (15 mg per dried gram); the upper figure assumes weak material (5 mg per gram), which you cannot confirm.

How the numbers are worked out

Research doses are milligrams of psilocybin

Trials give pure psilocybin, measured in milligrams, usually per 70 kg of body weight. The Johns Hopkins dose-effect study gave 0, 5, 10, 20 and 30 mg per 70 kg. [Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects, Psychopharmacology, 2011, read 28 October 2026] A cancer distress trial compared 1 or 3 mg per 70 kg with 22 or 30 mg per 70 kg. [Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer, Journal of Psychopharmacology, 2016, read 28 October 2026] Recent depression trials gave 25 mg: a single dose of 25 mg, 10 mg or 1 mg in one, [Single-dose psilocybin for a treatment-resistant episode of major depression, New England Journal of Medicine, 2022, read 28 October 2026] and two 25 mg doses three weeks apart in another. [Trial of psilocybin versus escitalopram for depression, New England Journal of Medicine, 2021, read 28 October 2026] In every one of these, participants were screened first and supported by trained staff throughout.

Mushrooms vary, a lot

Psilocybin is typically found at 0.1 to 1.5% of a mushroom's weight, and cultivated mushrooms have been shown to vary in psilocybin content by a factor of four. [The abuse potential of medical psilocybin according to the 8 factors of the Controlled Substances Act, Neuropharmacology, 2018, read 28 October 2026] A 2024 analysis of five Psilocybe cubensis strains found 0.88% to 1.36% psilocybin plus psilocin by dry weight, [Determination of psilocybin and psilocin content in multiple Psilocybe cubensis mushroom strains using liquid chromatography tandem mass spectrometry, Analytica Chimica Acta, 2024, read 28 October 2026] and another found stems held about half the concentration of caps, with individual mushrooms highly variable. [Stability of psilocybin and its four analogs in the biomass of the psychotropic mushroom Psilocybe cubensis, Drug Testing and Analysis, 2021, read 28 October 2026] We assume 5 to 15 mg per dried gram (0.5% to 1.5%), and size the cautious start for the strong end.

Fresh versus dried

Fresh mushrooms are mostly water. In one measured example, 2.5 kg of fresh Psilocybe cubensis dried to 140 g, roughly 18 to 1. [Basic extraction of psychoactive compounds from psychoactive organisms (US 11,642,385 B2), drying example, Psilo Scientific Ltd, US patent, 2023, read 28 October 2026] The calculator multiplies dried weights by 10, the usual rule of thumb. If the real ratio is higher, the fresh figure shown is the weaker side, never the stronger.

Body weight

Trial doses are often written per 70 kg, but a pooled analysis of 288 participants across ten studies, weighing 49 to 113 kg, found no significant association between body weight and the strength of the experience, and judged fixed doses reasonable. [Optimal dosing for psilocybin pharmacotherapy: considering weight-adjusted and fixed dosing approaches, Journal of Psychopharmacology, 2021, read 28 October 2026] Potency differences are far larger than weight differences, so the calculator shows what weight-scaling would mean but does not scale the range.

Truffles

Truffles are weaker per gram. Fresh Dutch truffles measured 0.6 to 1.7 mg of psilocybin per gram, [Magic truffles or Philosopher's stones: a legal way to sell psilocybin?, Drug Testing and Analysis, 2013, read 28 October 2026] against about 9 to 14 mg per gram of dried mushroom in the 2024 strain analysis, [Determination of psilocybin and psilocin content in multiple Psilocybe cubensis mushroom strains using liquid chromatography tandem mass spectrometry, Analytica Chimica Acta, 2024, read 28 October 2026] and DRUGSinfo notes that truffle strength varies from pack to pack. [Wat is het verschil tussen paddo's en truffels?, DRUGSinfo, Trimbos-instituut, read 28 October 2026] This calculator does not convert truffles. See mushrooms vs truffles and the Netherlands page, where truffle retreats are legal.

Before any dose: a safety checklist

For the whole preparation, read the four-week plan.

Questions

How many grams of mushrooms is a normal dose?

There is no reliable gram figure, because potency varies. A review reports psilocybin typically at 0.1 to 1.5% of a mushroom's weight, and cultivated mushrooms have been shown to vary by a factor of four. Research uses milligrams of pure psilocybin instead, most often 25 mg in recent trials. Assuming 5 to 15 mg per dried gram, 25 mg is roughly 1.7 to 5 g dried; start at the low end. [The abuse potential of medical psilocybin according to the 8 factors of the Controlled Substances Act, Neuropharmacology, 2018, read 28 October 2026] [Single-dose psilocybin for a treatment-resistant episode of major depression, New England Journal of Medicine, 2022, read 28 October 2026]

Should I dose by body weight?

Weight matters less than potency. A pooled analysis of 288 trial participants weighing 49 to 113 kg found no significant association between body weight and the strength of subjective effects, and concluded fixed doses were reasonable. [Optimal dosing for psilocybin pharmacotherapy: considering weight-adjusted and fixed dosing approaches, Journal of Psychopharmacology, 2021, read 28 October 2026]

How do fresh mushrooms compare with dried?

Fresh mushrooms are mostly water. In one measured example, 2.5 kg of fresh Psilocybe cubensis dried to 140 g, about 18 to 1. The calculator uses the usual rule of 10 g fresh to 1 g dried, which errs toward a smaller dose. [Basic extraction of psychoactive compounds from psychoactive organisms (US 11,642,385 B2), drying example, Psilo Scientific Ltd, US patent, 2023, read 28 October 2026]

Are truffles weaker than mushrooms?

Per gram, yes. One analysis of Dutch truffles found 0.6 to 1.7 mg of psilocybin per gram of fresh truffle, while a 2024 analysis of dried mushrooms found about 9 to 14 mg of psilocybin plus psilocin per gram. The Dutch drug information service says it is hard to judge how many truffles a trip takes. [Magic truffles or Philosopher's stones: a legal way to sell psilocybin?, Drug Testing and Analysis, 2013, read 28 October 2026] [Determination of psilocybin and psilocin content in multiple Psilocybe cubensis mushroom strains using liquid chromatography tandem mass spectrometry, Analytica Chimica Acta, 2024, read 28 October 2026] [Wat je moet weten over paddo's, DRUGSinfo, Trimbos-instituut, read 28 October 2026]

What is a heroic dose?

A popular name for a very high dose. The highest dose in the Johns Hopkins dose-effect study was 30 mg per 70 kg, and at 20 and 30 mg, 39% of screened volunteers had extreme anxiety or fear at some point, with trained monitors present. Do not take a high dose alone or as a first experience. [Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects, Psychopharmacology, 2011, read 28 October 2026]

When a retreat or licensed centre is the better choice

If you take any medication on the interaction checker, have a personal or family history of psychosis or bipolar disorder, have a heart condition, or have nobody sober and steady to sit with you, a setting with screening and trained staff is the safer choice. In trials, participants were screened first and supported by trained monitors throughout. [Human hallucinogen research: guidelines for safety, Journal of Psychopharmacology, 2008, read 28 October 2026]

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