Overview
Naltrexone is an opioid-receptor antagonist — it blocks the receptors that opioids and alcohol activate for reward. It's FDA-approved for alcohol use disorder and opioid use disorder, is not a controlled substance, is not addictive, and does not cause a high. Oral naltrexone is 50 mg once daily; Vivitrol is a monthly 380 mg intramuscular injection. Low-dose naltrexone (LDN, 1.5–4.5 mg) is used off-label for chronic pain and autoimmune conditions — we do not prescribe LDN over telehealth.
Symptoms to watch for
- For alcohol: reduced cravings, less reward from drinking, fewer heavy-drinking days
- For opioids: blocks the euphoric effect (prevents relapse); does not treat withdrawal
What else could this be?
- Acamprosate (Campral) — alternative for AUD, safer in liver disease
- Disulfiram (Antabuse) — alcohol-aversion, not craving-reduction
- Buprenorphine/Suboxone — different mechanism, used for opioid dependence with active withdrawal
How it's diagnosed
Naltrexone is prescribed after a clinical assessment for AUD or opioid use disorder. Baseline labs include LFTs (ALT/AST). For opioid use, you must be opioid-free for 7–10 days (or 14 days for methadone) before starting — Clindle helps time this carefully or refers to buprenorphine when active withdrawal is present.
Treatment
Oral naltrexone — 50 mg once daily; can be taken with food to reduce nausea. Sinclair Method — 50 mg one hour before drinking. Vivitrol — 380 mg IM every 4 weeks, given at a local clinic. Common side effects (first week): nausea, headache, fatigue, dizziness — usually resolve. Long-term use is safe with periodic LFT monitoring.
When to book a visit
Book a Clindle visit for alcohol use disorder or to continue naltrexone you were already prescribed. We do not prescribe naltrexone for opioid use disorder over telehealth in isolation — that's coordinated with a local addiction-medicine specialist.
Book online todayFrequently asked
Is naltrexone addictive?
No. Naltrexone does not cause dependence, tolerance, or a withdrawal syndrome when stopped.
Can I drink on naltrexone?
You can, but it won't feel as rewarding — that's the point. Unlike disulfiram, naltrexone does not cause a violent reaction if you drink.
Oral naltrexone vs Vivitrol — which is better?
Adherence is the biggest factor. Vivitrol (monthly injection) removes daily-pill compliance; oral is cheaper and easier to start. Both are effective.
Does insurance cover naltrexone?
Generic oral naltrexone is inexpensive (often $30–50/month cash) and covered by most plans. Vivitrol is expensive but usually covered with prior authorization.
What is low-dose naltrexone (LDN)?
1.5–4.5 mg used off-label for fibromyalgia, chronic pain, and autoimmune conditions. Evidence is early. Clindle does not prescribe LDN over telehealth — see a specialist experienced with it.