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    ๐Ÿงช This is a research chemical with limited data on its long-term health effects, toxicity profile, and safe dosage ranges.

    25I-NBF Encyclopedic
    Encyclopedic
    Typical encyclopedia coverage. Cross-reference for important decisions.
    • 4 corroborating sources
    • 3 ROAs with full dose ladders
    • duration data present
    • 28 combo interactions documented
    • classified Tentative
    • classified Research-chemical

    Aliases: 2c-i-nbf, Nbf-2c-i, Cimbi-21

    Psychedelic Stimulant Research-chemical

    Summary dose.wiki TripSit

    25I-NBF (Cimbi-21) is a psychedelic phenethylamine and research chemical. It acts primarily through potent partial agonism at 5-HT2A and 5-HT2C receptors with bias toward ฮฒ-arrestin 2 signaling, while peripheral ฮฑ-adrenergic activity contributes to vasoconstriction and cardiovascular strain. It is approximately 6-8 times less potent than 25I-NBOMe but shares a similar qualitative effect profile and comparable safety concerns. Oral bioavailability is low, so sublingual, buccal, or insufflated administration is typically used.

    Dose Information Drugs.Wiki

    Dose basis. Sublingual: Ranges are primarily from user reports and harm-reduction compendia; individual response varies widely. Volumetric dosing is strongly recommended due to mg-level potency and dosing error risk. Insufflated: Intranasal use increases adverse vasoconstrictive and cardiovascular effects; liquid (volumetric) nasal dosing is advised over dry powder to reduce hot-spots and local tissue irritation. (Dose figures and this note are from Drugs.Wiki.)

    ROA Light Common Strong Heavy
    Sublingual 2-4mg 4-8mg 8-12mg 12mg+
    Insufflated 1-2mg 2-5mg 5-8mg 8mg+
    Oral 6-10mg 10-16mg 16-22mg 22mg+
    Light Common Strong Heavy
    Sources

    Sublingual

    Dose ladder — Drugs.Wiki

    Insufflated

    Dose ladder — Drugs.Wiki

    Oral

    Dose ladder — Drugs.Wiki

    Onset, Duration & After-effects dose.wiki Drugs.Wiki

    ROA Onset Comeup Peak Offset After Effects Total
    Sublingual 10-30 min 30-60 min 2-4 hrs 2-4 hrs 2-8 hrs 4.67-9.5 hrs
    Insufflated 5-15 min 20-45 min 2-4 hrs 2-4 hrs 2-8 hrs 4.41-9 hrs
    Oral 30-60 min 45-90 min 2-4 hrs 2-4 hrs 2-8 hrs 5.25-10.5 hrs

    Effect Profile

    Scores (0–10) curated from multiple sources:

    • Effect keyword matching from PsychonautWiki catalog
    • Weighted by importance: core (×3), major (×2), minor (×1)

    Full methodology

    Psychedelic 6.2
    Strong 6/10

    Strong visuals with moderate headspace and body load, mild auditory effects

    Visual Intensity ×3
    8
    colour enhancement drifting tracers
    Headspace Depth ×3
    6
    conceptual thinking thought loops time distortion confusion
    Auditory Effects ×1
    4
    auditory distortion
    ⚠ Body Load / Somatic Effects ×1
    6
    vasoconstriction nausea increased heart rate
    Stimulant 3.1
    Light+ 3/10

    Moderate euphoria with strong anxiety/jitters, low stimulation and focus

    Stimulation / Energy ×3
    3
    stimulation
    Euphoria / Mood Lift ×2
    6
    physical euphoria euphoria
    Focus / Productivity ×2
    2
    analysis enhancement
    ⚠ Anxiety / Jitters ×1
    10
    anxiety restlessness increased heart rate vasoconstriction thought loops
    View methodology →

    Tolerance

    Build-up develops rapidly after a single use
    Reset 7โ€“14 days for baseline

    Tolerance Decay

    Full tolerance 1d Half tolerance 7d Baseline ~14d

    Rapid tolerance build similar to NBOMe/LSD is reported anecdotally; noticeable tolerance persists several days and may take 1โ€“2 weeks to normalize.

    Cross-Tolerances

    LSD/psilocybin/2C-series/NBOMe-series

    Effects dose.wiki

    Positive
    Negative
    Neutral
    Positive
    Negative
    Neutral
    Positive
    Neutral

    Combinations

    Cross-Check 25I-NBF with another substance

    25I-NBF's nerd page Pharmacology, chemical data, effect profiles, and more
    →

    Helpful Links

    ๐Ÿ“– dose.wiki
    Add to PsychonautWiki Journal

    The PsychonautWiki Journal logging app doesn't include every substance. To track 25I-NBF 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 "25I-NBF (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
    25I-NBF
    Unit
    mg
    Description 
    25I-NBF
Source: SubstanceSearch (substancesearch.com)

Sublingual dose (mg): threshold 1-2 ยท light 2-4 ยท common 4-8 ยท strong 8-12 ยท heavy 12+
Insufflated dose (mg): threshold 0.5 ยท light 1-2 ยท common 2-5 ยท strong 5-8 ยท heavy 8+
Oral dose (mg): threshold 4 ยท light 6-10 ยท common 10-16 ยท strong 16-22 ยท heavy 22+

Sublingual duration: onset 10-30m ยท come-up 0.5-1h ยท peak 2-4h ยท offset 2-4h ยท total 4.67-9.5h ยท after-effects 2-8h
Insufflated duration: onset 5-15m ยท come-up 20-45m ยท peak 2-4h ยท offset 2-4h ยท total 4.41-9h ยท after-effects 2-8h
Oral duration: onset 0.5-1h ยท come-up 0.75-1.5h ยท peak 2-4h ยท offset 2-4h ยท total 5.25-10.5h ยท after-effects 2-8h

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 ~ 6 mg (Sublingual).

    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.