[Solved] Taper off diazepam before taking psilocybin

The half-life of diazepam (Valium) is very long. In adults, it ranges from 24 to 48 hours. The active metabolite (N-desmethyldiazepam) even has a half-life of up to 100 hours.

The half-life varies from person to person and depending on the situation, as is the case with older people: the half-life can be as long as 70 to 100 hours, meaning the medicine remains in the body for much longer.

However, the calming effect lasts for 8–12 hours.

What does this mean for the inhibitory effect on psilocybin?

In practice, we have observed that amongst people who continue to take benzodiazepines, a few experience no reduction in effects whatsoever. A large group, however, does experience reduced effects, such as fewer visual effects and a diminished emotional response. This group often increases their dose to compensate. A third, smaller group experiences significantly reduced effects and little to no visual effects. Consequently, this latter group experiences very little during such a day and progress is often minimal.

How long do you need to have stopped taking diazepam?

A commonly used pharmacokinetic rule of thumb is to calculate using five times the half-life. After five half-lives, approximately 97 per cent of a substance has been eliminated. In the case of diazepam, however, this calculation is complex, as the active metabolite N-desmethyldiazepam can also persist for a long time.

Assuming a half-life of up to 100 hours for this metabolite, five half-lives would amount to approximately 500 hours, or around 21 days. In older people, with long-term use, higher doses or impaired liver function, it may take longer for the sedative effect to have largely worn off.

A practical, conservative guideline is therefore as follows: in the case of occasional and low-dose use, do not base your calculations solely on the last tablet, but allow for at least a few days to a week; in the case of regular use, it is pharmacologically safer to allow approximately two to three weeks after stopping completely. However, this is no guarantee of a fully uninhibited experience, nor is it a substitute for individual medical advice.

On stopping or tapering off safely:

Do not stop taking diazepam suddenly if you have been taking it for more than about two weeks, on a daily basis or in higher doses. Stopping abruptly can cause withdrawal symptoms, including severe anxiety, insomnia and, in some cases, epileptic seizures. Long-term use usually requires a gradual reduction in consultation with the prescriber, GP or pharmacist. 

The priority, therefore, is not to stop as quickly as possible so that the psilocybin has a stronger effect, but to taper off safely and steadily. A psychedelic session during acute benzodiazepine withdrawal is generally inadvisable, as withdrawal itself can exacerbate anxiety, sleep problems and physical dysregulation.

To be content with what may be a reduced effect

Some people who take benzodiazepines choose, in consultation with their prescriber, not to take the medication for 24 to 48 hours before a session and to resume taking it afterwards in accordance with their prescription. In the case of diazepam, such a short break does not mean that the drug has been completely cleared from the body: due to its long half-life and active metabolites, a sedative effect may still be present.

Such a temporary interruption may partially reduce the dampening effect of psilocybin in some people. However, the effect is unpredictable and can range from barely noticeable to still significantly reduced. Anyone opting for this approach must therefore accept that the experience may be less intense, for example with fewer visual effects or less emotional depth.

Always discuss the best course of action with your doctor. For some people, this may involve tapering off the medication, continuing to take it, or missing a few doses.