Naltrexone is best known as a treatment for opioid and alcohol addiction, but what many people don’t realize is that the dose makes all the difference. At standard doses, naltrexone blocks opioid receptors to help prevent relapse. But at low doses, it works completely differently—modulating the immune system, reducing inflammation, and even helping with chronic pain.
So, how does low-dose naltrexone (LDN) differ from full-dose naltrexone? And which one is best for your needs? Let’s break it down.
What Is Naltrexone?
Naltrexone is a medication that blocks opioid receptors in the brain. It was originally developed to treat opioid addiction by preventing opioids from producing a high.
Over time, researchers discovered that at much lower doses, naltrexone has entirely different effects, including reducing pain, inflammation, and even autoimmune activity.
The two main ways naltrexone is prescribed are:
- Standard-dose naltrexone (50 mg – 100 mg per day) – Used for opioid and alcohol addiction treatment.
- Low-dose naltrexone (LDN) (0.5 mg – 4.5 mg per day) – Used for chronic pain, autoimmune disorders, and inflammatory conditions.
Same drug, different effects—but why?
LDN vs. Full-Dose Naltrexone: Key Differences
| Feature | Low Dose Naltrexone (LDN) | Full-Dose Naltrexone |
| Typical Dosage | 0.5 mg – 4.5 mg per day | 50 mg – 100 mg per day |
| Main Uses | Autoimmune diseases, chronic pain, inflammation, mental health | Opioid & alcohol addiction treatment |
| How It Works | Modulates immune function, reduces inflammation, increases endorphins | Blocks opioid receptors to prevent relapse |
| Side Effects | Mild (vivid dreams, headaches, temporary fatigue) | Nausea, anxiety, liver enzyme changes |
| Availability | Compounded at specialty pharmacies | Standard prescription at most pharmacies |
Let’s take a deeper look at how each dose works differently.
How Full-Dose Naltrexone Works (50 mg – 100 mg)
At standard doses, naltrexone is an opioid receptor blocker (antagonist).
How It Works for Addiction
- Blocks opioid receptors, preventing opioids from causing euphoria.
- Reduces cravings for opioids and alcohol.
- Prevents relapse by making opioid use ineffective.
Example: Someone recovering from heroin addiction takes 50 mg of naltrexone daily. If they relapse and use heroin, they won’t feel high, making them less likely to use again.
Conditions Treated with Full-Dose Naltrexone
- Opioid addiction (prevents relapse)
- Alcohol use disorder (reduces cravings)
- Off-label: Binge-eating disorder, impulse control disorders
Who Should Take Full-Dose Naltrexone?
- People recovering from opioid or alcohol addiction
- Individuals looking to reduce cravings and prevent relapse
- Those who are completely off opioids before starting treatment
Not ideal for: People with chronic pain, autoimmune disorders, or inflammation, as it doesn’t have the immune-modulating benefits of LDN.
How Low-Dose Naltrexone (LDN) Works (0.5–4.5 mg per day)
LDN is taken at a much lower dose—often just 1–4 mg per day. Instead of fully blocking opioid receptors, LDN temporarily blocks them for a few hours. This triggers the body to increase its natural endorphin production, which can:
- Reduce pain sensitivity
- Regulate immune system function
- Decrease inflammation
Conditions Treated with LDN
- Chronic pain disorders (fibromyalgia, neuropathy)
- Autoimmune diseases (multiple sclerosis, Crohn’s disease, rheumatoid arthritis, lupus)
- Inflammatory conditions (long COVID, chronic fatigue syndrome, irritable bowel syndrome)
- Mental health conditions (depression, PTSD, anxiety, post-concussion syndrome)
Who Should Take LDN?
- People with chronic pain, autoimmune conditions, or inflammation
- Those looking for a medication that supports natural healing and immune balance
- Individuals who don’t need full opioid receptor blockade
Not ideal for: People who need strong opioid blocking effects, like those in opioid addiction recovery.
Can You Take LDN and Full-Dose Naltrexone Together?
No—you shouldn’t take them together since they work in opposite ways.
- LDN is for chronic pain and immune regulation, where opioid receptor modulation helps balance the body.
- Full-dose naltrexone is for addiction treatment, where opioid receptors need to be fully blocked.
If you’re considering switching between the two, talk to a doctor to do it safely.
How to Get Low-Dose Naltrexone Online
Since LDN is not FDA-approved for most conditions, it is typically prescribed off-label and compounded at specialty pharmacies.
- Online telemedicine services (like QuickMD) offer LDN prescriptions.
- Compounding pharmacies can prepare LDN in the correct dosage.
- Insurance may not cover LDN, so costs vary.
QuickMD: Fast, Affordable Naltrexone Prescriptions
- Online doctor visits—no in-person clinic required
- LDN prescriptions sent to your preferred pharmacy
- Expert guidance on dosing and safety
Final Thoughts
While LDN and full-dose naltrexone come from the same drug, they serve completely different purposes.
- Full-dose naltrexone is best for opioid and alcohol addiction recovery.
- LDN is best for chronic pain, inflammation, and autoimmune conditions.
If you’re considering trying LDN for chronic pain or immune support, talk to a knowledgeable doctor about whether it’s right for you.
Need a prescription for LDN? Book an appointment with QuickMD today.
