Side-effect tracker for GLP-1 drug users

What to build

A mobile app for GLP-1 drug users (Ozempic, Wegovy, Mounjaro) that logs hair, nail, and muscle-loss symptoms over time, correlates them with dose/diet entries, and nudges users on daily protein, biotin, collagen, and vitamin intake to offset nutrient deficiencies.

Hair loss was the first widely reported GLP-1 side effect; nail brittleness is now surfacing as a second, related cosmetic/nutrient-deficiency symptom, and the same vocal online user base swapping remedies is a ready-made audience for a tracking and coaching app.

Demand

GLP-1 users experiencing rapid weight loss and visible cosmetic side effects are already trading tips in forums and groups; the Gizmodo piece on nail trouble getting strong Hacker News engagement signals this is spreading beyond a niche complaint into broader awareness.

• Hacker NewsNews

  'Hair Loss Was Just the Start. Ozempic Users Are Also Reporting Nail Trouble' — 45 points, 38 comments on HN, indicating high engagement with the topic among a tech-savvy audience.

• Signal title source (unspecified outlet)News

  Media coverage framing nail trouble as an emerging secondary side effect pattern among GLP-1 users, following earlier widely-reported hair loss coverage.

• Online GLP-1 user community (implied)Anecdotal

  Opportunity brief notes a 'large, vocal online community of GLP-1 users already swapping tips' on hair loss, brittle nails, and muscle loss, pointing to active peer-to-peer demand for solutions.

Stack

• React Native / Expo
• Supabase (auth + Postgres for symptom/dose logs)
• RevenueCat (subscription billing)
• OpenAI API (symptom-pattern summaries and reminders copy)
• Amazon Associates / iHerb affiliate API (supplement links)
• Push notifications (Expo Notifications) for daily nutrient nudges

Solo + AI difficulty

The core build is easy for a solo AI-assisted developer: symptom logging, dose tracking, and reminder notifications are standard CRUD + push-notification patterns shippable in 2-4 weeks. The harder parts are get the supplement/nutrient guidance content right without making implied medical claims, and building enough trust (and retention hooks like trend charts) to beat free Reddit/Facebook groups as the default place people go.

Entry threshold

A solo builder can ship a simple tracking and reminder app with AI-assisted development in two to four weeks using off-the-shelf health-tracker templates; no medical license is needed since it is informational rather than diagnostic, but content must avoid medical claims.

Window

12-18 months

Where to find first users

• r/Ozempic, r/Semaglutide, r/Mounjaro, r/WegovyWeightLoss subreddits
• GLP-1 Facebook support groups
• TikTok/Instagram creators covering Ozempic side effects
• Product Hunt launch targeting health and weight-loss tools

Counter-signals & risks

• Anecdotal self-reported symptoms on forums/social media are not clinically validated and may not reflect true prevalence or causation from GLP-1 drugs versus rapid weight loss or caloric deficit generally.

• A companion/logging app faces low switching cost and competition from existing general health-tracking apps, nutrition apps, and free online communities (Reddit, Facebook groups) already serving this need.

• Regulatory and liability risk around app-driven supplement recommendations (biotin, collagen, protein) for a population on prescription medication, especially if marketed with implied medical claims.