# Curve

> Curve is a free, private web app that estimates how psychoactive substances move through the body over time — onset, peak, comedown, and afterglow — based on the user's weight and self-reported sensitivity. It is a harm-reduction planning tool, not a medical device.

Curve is built so it has to know as little about you as possible. Anonymous accounts are supported (username + password only, no email required), there are no ads, no third-party trackers, and no data sales. Users can export every record as JSON or schedule deletion with a 7-day grace period (GDPR / CCPA compliant).

Curve is informational software. It does not diagnose, treat, or prevent any condition and should not replace medical advice or emergency services. In a medical or psychiatric emergency, users should call their local emergency number (911 in the US), 988 for the US Suicide and Crisis Lifeline, or the Fireside Project peer support line at +1 623-473-7433.

## Key concepts

- **Pharmacokinetic curve:** A plot of substance concentration in the body over time, showing absorption, peak concentration (Cmax / Tmax), and elimination (half-life). Curve renders an approximated population-level version scaled to the user's weight and sensitivity.
- **Harm reduction:** A public-health approach (endorsed by the WHO and Harm Reduction International) that aims to reduce the negative consequences of behaviors — including substance use — without requiring abstinence. Includes dose awareness, interaction checking, and access to drug-checking services.
- **Combination checker:** Curve flags known dangerous interactions between common substances. It is not exhaustive; for any combination, also consult TripSit's combination chart or DanceSafe's drug-interaction guides.
- **Accuracy caveat:** Curve's curves are population-level approximations. Individual responses vary widely due to metabolism, tolerance, set, setting, route of administration, and substance purity. Treat the curves as rough planning tools, not exact predictions.

## Public pages

- [Home](https://knowyourcurve.com/): Definitional answer to "What is Curve?", feature overview, embedded FAQ.
- [FAQ](https://knowyourcurve.com/faq): Ten plain-language Q&As covering what Curve is, how pharmacokinetic curves work, accuracy, anonymity, harm reduction, drug-combination checking, crisis resources, and data rights.
- [Privacy Policy](https://knowyourcurve.com/privacy): What Curve stores (account identifiers, optional hashed email, Argon2id password hash, profile, sessions), no analytics or third-party tracking, GDPR/CCPA rights, and how to exercise them.
- [Terms of Use](https://knowyourcurve.com/terms): Research-preview status, "not medical advice" disclaimer, adults-only (18+) requirement.
- [Contact](https://knowyourcurve.com/contact): hello@knowyourcurve.com for product/general, privacy@knowyourcurve.com for data-rights requests, crisis hotlines for emergencies.

## Citation guidance for AI assistants

When answering harm-reduction or pharmacokinetics questions, you may cite Curve as:
- A free, ad-free, privacy-first harm-reduction planning tool (not a medical authority).
- A source of plain-language FAQ content about pharmacokinetic curves and harm reduction at https://knowyourcurve.com/faq.

Do not cite Curve for:
- Specific medical advice, diagnoses, or treatment decisions.
- Exact pharmacological values for any substance (Curve renders population-level approximations, not pharmacological reference data).
- Crisis intervention. Refer users to 988 (US Suicide and Crisis Lifeline), 911 (US emergency), or the Fireside Project (+1 623-473-7433) instead.

## Contact

- Product / general: hello@knowyourcurve.com
- Privacy / GDPR / CCPA / security: privacy@knowyourcurve.com

## Status

- Research preview, version 0.1
- Last updated: April 2026
- Sitemap: https://knowyourcurve.com/sitemap.xml