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§2.3.15 · ChemicalsStimulants

HDMP-28

Methylnaphthidate

Acute: High riskDependency: High risk

Images

Quick reference

Routes
Insufflated
Form
Powder

Duration

Onset
5 Minutes
Total duration
3 Hours

Experience

Primary effects

  • A stimulant producing an intense, strong, and long-lasting 'buzz'.
  • Causes pupil dilation and jaw tension.

Peak character

  • The experience was 'nice enough' but accompanied by a high body load.

Negatives / side effects

  • Significant nose-burn and harshness if insufflated, potentially leading to a mild headache.
  • Causes high jaw tension and potential for compulsive redosing.
  • Can lead to a lengthy period of residual stimulation and inability to sleep if too much is taken.

Aftereffects / comedown

  • Residual stimulation can last into the following late-afternoon if taken in the evening, causing sleep deprivation.
  • May contribute to a general feeling of malaise after the experience.

Reference dosage

Reference ranges from third-party harm-reduction databases. Individual response varies enormously — start lower than you think.

oral
threshold5mg+
light10mg+
common20mg+
strong40mg+

Reagent testing

Recommended reagents
Expected reactions
MandelinYellow → orange
MarquisOrange/brown

Adulterant detection: Hydroxymethylphenidate analogue. High potency; limited specific reagent data.

Methylphenidate-class stimulant. Higher potency than MPH — precise dosing essential.

Source

Reference fields and narrative for HDMP-28 extracted from The Drug Users Bible by Dominic Milton Trott (MxZero Publishing, 2022).

drugusersbible.com

Harm reduction notice

This platform provides educational and harm-reduction information adapted from public reference material. It does not endorse, encourage, or facilitate drug use. It is not medical advice. If you or someone near you may be in a medical emergency, contact local emergency services immediately.