Ethylnaphthidate (HDEP-28)
Ethylnaphthidate (HDEP-28) is the ethyl-ester naphthyl analogue in the methylphenidate/phenidate family, a potent dopamine reuptake inhibitor sold as a research chemical. Like other naphthidates it is far more potent than methylphenidate in preclinical assays and has no human safety characterisation.
01 Overview
Ethylnaphthidate belongs to the naphthidate subclass of phenidate stimulants, structurally related to HDMP-28 with an ethyl ester. It has been offered on research-chemical markets as a strong, long-lasting stimulant.
There is no clinical human data. Given the very high dopamine transporter potency documented for naphthidates, it should be treated as having substantial abuse potential and unknown but plausibly serious cardiovascular and psychiatric toxicity.
02 Mechanism
Potent dopamine and norepinephrine reuptake inhibitor of the naphthyl-phenidate class.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Common (approximate, anecdotal) | 5–15 mg | Oral | Potent; user-reported only. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Long-lasting stimulationExtended wakefulness and focus reported. | Strong | Anecdotal | |
| Redosing compulsionPotent phenidate reinforcement drives compulsive use. | Moderate-strong | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Severe insomniaLong duration produces marked sleep loss. | Moderate | Common | Anecdotal | |
| Vasoconstriction and cardiovascular strainCold extremities, tachycardia and hypertension expected from potent phenidate activity. | Severe | Unknown | Unconfirmed |