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    Disclaimer
    ๐Ÿงช This is a research chemical with limited data on its long-term health effects, toxicity profile, and safe dosage ranges.
    โš  Opioids carry significant risk of respiratory depression, physical dependence, and fatal overdose. Never combine with other depressants.

    U-51754 Encyclopedic
    Encyclopedic
    Typical encyclopedia coverage. Cross-reference for important decisions.
    • 2 corroborating sources
    • 1 ROA with full dose ladder
    • duration data present
    • 29 combo interactions documented
    • classified Tentative
    • classified Research-chemical

    Aliases: Methene-u-47700, methene-u47700

    Depressant Research-chemical Opioid

    Summary TripSit

    A very potent opioid, that seems to have a fair bit of ฮบ-opioid action. So Dyshopria, Auditory hallucinations can be an effect. Is an analogue of U-47700.

    Dose Information dose.wiki TripSit

    ROA Light Common Strong Heavy
    Rectal 1-3mg 3-5mg 5-10mg 10mg+
    Light Common Strong Heavy
    Sources

    Rectal

    Dose ladder — dose.wiki, TripSit

    Onset, Duration & After-effects TripSit

    ROA Onset After Effects Total
    Rectal 5-10 min 3-6 hrs 1-2 hrs

    Tolerance

    Build-up develops within days of regular use; analgesic tolerance faster than respiratory depression tolerance
    Reset Falls quickly once you stop, at a rate you can't judge. After any break, treat your tolerance as gone.

    No tolerance chart. Our decay curves for opioids were estimates, and a curve can make tolerance look longer-lasting than it is, which is the dangerous direction.

    Opioid tolerance drops fast when you stop, and even a few days off can be enough, so a dose that used to be normal can now stop your breathing. Overdose deaths rise sharply after prison, detox or leaving treatment, and tolerance also falls during a hospital stay. After any break, start with a much smaller amount, try a test dose first, don't use alone, and keep naloxone within reach. Alcohol, benzodiazepines, gabapentinoids and other sedatives make an opioid overdose much more likely.

    Sources: FRANK: heroin ยท National Harm Reduction Coalition ยท WHO: opioid overdose ยท Merrall et al. 2010 ยท Binswanger et al. 2007 ยท Strang et al. 2003 ยท FDA 2019: gabapentinoids and breathing

    Combinations TripSit

    Cross-Check U-51754 with another substance

    U-51754's nerd page Pharmacology, chemical data, effect profiles, and more
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    Helpful Links

    ๐Ÿ“– TripSit
    Add to PsychonautWiki Journal

    The PsychonautWiki Journal logging app doesn't include every substance. To track U-51754 there, start adding an ingestion, search for the name, and choose to add it as a custom substance. Paste these values:

    ⬇ Download import file Import this file as custom substances and you get "U-51754 (Substance Search)" with every route's full dose ladder and timeline, no typing. Works on iOS and Android (v15+); the format is confirmed by the app's developer. The manual values below work for older versions.
    Name
    U-51754
    Unit
    mg
    Description 
    U-51754
Source: SubstanceSearch (substancesearch.com)

Rectal dose (mg): light 1-3 ยท common 3-5 ยท strong 5-10 ยท heavy 10+

Rectal duration: onset 5-10m ยท total 1-2h ยท after-effects 3-6h

Note: ranges are harm-reduction guidance, not a prescription. Start low, go slow, and test your substances.

    Tip: for quicker logging you can also add a Custom Unit in the app, e.g. common dose ~ 4 mg (Rectal).

    The app keeps custom substances simple, so the full dose ranges live in the description text above. Ranges are harm-reduction guidance, not a prescription.