The concept of “redosing” has become an across-the-board rule of thumb, without the pharmacokinetic consequences ever being communicated. Specifically:
- MDMA: Half-life 6–9 h. A second dose after 1 hour means both plasma levels add up. The risk of hyperthermia and hyponatremia rises significantly.
- Cocaine: Half-life 1 h, rapid tolerance, strong temptation to binge. Cardiac risks accumulate.
- GHB: Half-life 30 min, an extremely narrow window; redosing without a clear pause is one of the most common causes of emergencies.
- Cathinones (3-MMC, 4-MMC): short half-life, binge pattern typical, cardiac and psychological complications.
Classic harm-reduction advice: one dose per session, a clear pause until the next session (at least weeks). If you do redose: smaller dose, long gap, awareness of your own physical reaction.