25I-NBF
Encyclopedic
Encyclopedic
Typical encyclopedia coverage. Cross-reference for important decisions.
- 4 corroborating sources
- 3 ROAs with full dose ladders
- duration data present
- 18 combo interactions documented
- classified Tentative
- classified Research-chemical
- 4 corroborating sources
- 3 ROAs with full dose ladders
- duration data present
- 18 combo interactions documented
- classified Tentative
- classified Research-chemical
Aliases: 2c-i-nbf, Nbf-2c-i, Cimbi-21
Summary
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
Dose basis. 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. 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+ |
Onset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | Total |
|---|---|---|---|---|---|
| Sublingual | 10-30 min | 30-60 min | 2-4 hrs | 2-4 hrs | 4.67-9.5 hrs |
| Insufflated | 5-15 min | 20-45 min | 2-4 hrs | 2-4 hrs | 4.41-9 hrs |
| Oral | 30-60 min | 45-90 min | 2-4 hrs | 2-4 hrs | 5.25-10.5 hrs |
Effect Profile
Scores (1–10) curated from multiple sources:
- Effect keyword matching from PsychonautWiki catalog
- Weighted by importance: core (×3), major (×2), minor (×1)
Strong visuals with moderate headspace and body load, mild auditory effects
Strong anxiety/jitters with moderate euphoria, low stimulation and focus
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:
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.
Tolerance
Tolerance Decay
Acute tolerance: develops within a single session โ the reset numbers above apply after sustained heavy use, not after one binge. Within-session tachyphylaxis usually resets largely overnight.
Rapid tolerance build similar to NBOMe/LSD is reported anecdotally; noticeable tolerance persists several days and may take 1โ2 weeks to normalize.
Cross-Tolerances
Effects
- Stimulation
- Physical euphoria
- Increased heart rate
- Vasoconstriction
- Nausea
- Pupil dilation
- Insomnia
- Restlessness
- Sedation
- Spontaneous bodily sensations
- Euphoria
- Empathy
- Conceptual thinking
- Analysis enhancement
- Anxiety
- Confusion
- Thought loops
- Memory suppression
- Motor control loss
- Time distortion
- Colour enhancement
- Bodily control enhancement
- Tactile enhancement
- Color enhancement
- Tracers
- Increased music appreciation
- Visual patterning
- Closed-eye visuals
- Drifting
- Auditory distortion
Combinations
Cross-Check 25I-NBF with another substanceHelpful Links
Report an issue or suggest an edit
Spotted incorrect or dangerous information, have a correction, a new study, or a useful addition for 25I-NBF? Let us know. Reports are reviewed by moderators — this is not posted publicly.