harm reduction guide

2C-B Harm Reduction Guide

also known as: nexus, 4-bromo-2,5-dimethoxyphenethylamine

2C-B is a phenethylamine psychedelic with effects that blend elements of MDMA and classic psychedelics. Developed by Alexander Shulgin, it's known for being highly dose-sensitive and producing colorful visual effects alongside sensory amplification. Duration is shorter than LSD, making it popular for recreational use.

Have a specific question about 2C-B?

Ask our AI — grounded in curated harm reduction sources, not guesswork.

ask the AI →

Effects

  • ✦Bright, colourful visual hallucinations and patterning
  • ✦Heightened sensory pleasure (music, touch, taste)
  • ✦Empathic feelings similar to MDMA but less intense
  • ✦Mental clarity retained more than with classic psychedelics
  • ✦Strong body high and physical sensations
  • ✦Erotic enhancement at moderate doses

Duration

4–6 hours

Dosage

Individual sensitivity varies. Always start at the lower end if you're new to this substance.

Threshold5–10 mg
Light10–15 mg
Common15–25 mg
Strong25–35 mg
Heavy35+ mg

Risks

  • ⚠Extreme dose-sensitivity — a few mg difference significantly changes intensity
  • ⚠Anxiety and difficult experiences at higher doses
  • ⚠Nausea on come-up
  • ⚠Adulterants are common; NBOMe compounds are sometimes sold as 2C-B (much more dangerous)

Harm Reduction Tips

  • ✓Test your substance — an Ehrlich reagent will distinguish 2C-B from NBOMe compounds (which are dangerous)
  • ✓Be extremely careful with dosing — differences of 5 mg have large effects
  • ✓Start at 10–12 mg if new to psychedelics or this substance
  • ✓Insufflating (snorting) dramatically intensifies and shortens effects — use oral route first
  • ✓Eat lightly 2–3 hours before to reduce nausea
  • ✓The combination with MDMA ('candy flip') is popular but amplifies both substances — use much lower doses of each

Dangerous Combinations

Always research interactions before combining any substances.

  • ✕MAOIs — serotonin syndrome risk
  • ✕Lithium — seizure risk
  • ✕SSRIs — reduces effects but possible serotonin complications
  • ✕High-dose stimulants — cardiovascular strain

Still have questions about 2C-B?

Our AI gives personalised harm reduction answers grounded in curated reference material — dosage questions, combinations, set & setting, and more.

ask for free →

3 questions per day · no credit card

This guide is for educational and harm reduction purposes only. It is not medical advice. Content informed by Psychonaut Wiki.