Getting low dose naltrexone (LDN) requires a prescription from a licensed medical provider, followed by filling that prescription at a compounding pharmacy. LDN is not available as a standard medication at regular pharmacies because the FDA has only approved naltrexone at higher doses (50 to 100 mg) for treating alcohol and opioid dependence. The low doses used for pain and immune conditions, typically 0.5 to 6 mg, are prescribed off-label, and only compounding pharmacies can prepare the medication at these smaller strengths.
Why You Need a Compounding Pharmacy
No pharmaceutical company manufactures naltrexone in the low doses needed for LDN therapy. Standard naltrexone tablets come in 50 mg, which is roughly 10 times the typical LDN dose. A compounding pharmacy custom-prepares the medication in the exact strength your doctor prescribes, usually as capsules, sublingual tablets, or transdermal preparations. Most local compounding pharmacies offer LDN in capsule form, while a few mail-order companies also dispense scored tablets.
Not every pharmacy compounds medications, so you may need to call around or search online for a compounding pharmacy near you. Several mail-order compounding pharmacies specialize in LDN and can ship directly to your home if there isn’t a local option.
Finding a Prescriber
The biggest hurdle for most people is finding a doctor willing to prescribe LDN. Because it’s used off-label, not every physician is familiar with it or comfortable prescribing it. Here are the most common routes people take:
- Your current doctor. Start by asking your primary care physician or specialist. If you’re being treated for fibromyalgia, multiple sclerosis, rheumatoid arthritis, Crohn’s disease, or another chronic pain or autoimmune condition, your doctor may already be aware of LDN’s use in these areas. Bring specific research if they’re unfamiliar.
- Integrative or functional medicine doctors. These practitioners tend to be more open to off-label prescribing and often have experience with LDN specifically.
- Telehealth services. Several online clinics now offer LDN consultations. These virtual appointments connect you with a provider who can evaluate your history, write the prescription, and send it directly to a compounding pharmacy.
- LDN-specific directories. Patient advocacy organizations maintain lists of doctors who prescribe LDN, searchable by location.
What the Prescription Looks Like
LDN prescriptions follow a gradual titration schedule, meaning you start at a low dose and increase over several weeks. A common approach recommended by the American Fibromyalgia Syndrome Association involves two separate prescriptions:
The first script covers the ramp-up period: 1.5 mg capsules of immediate-release naltrexone, with instructions to take one capsule at bedtime for the first week, then two capsules at bedtime for the second week. The second script is for the maintenance dose: 4.5 mg capsules taken once at bedtime, typically a 90-day supply.
If you tend to be sensitive to new medications, your doctor can extend the initial titration to two weeks at each step instead of one. Most people take LDN at bedtime, though some prescribers adjust timing based on how patients respond.
What It Costs
LDN is relatively inexpensive compared to many chronic disease medications. Most people pay $30 to $60 per month at a compounding pharmacy, though the exact cost depends on your dosage, the pharmacy, and your location. Insurance coverage for compounded medications is inconsistent. Some plans cover part of the cost, but many do not, so expect to pay out of pocket. Even without insurance, the monthly cost stays manageable for most people.
Conditions Prescribers Use It For
LDN is most commonly prescribed for chronic pain and autoimmune conditions. The list includes fibromyalgia, multiple sclerosis, complex regional pain syndrome, rheumatoid arthritis, and Crohn’s disease. Some practitioners also prescribe it for neuropathic pain and as part of integrative cancer care. More recently, researchers have studied LDN for post-COVID fatigue syndrome, with a completed 160-person clinical trial using doses starting at 1 mg per day and increasing to 4.5 mg over 16 weeks.
At these low doses, naltrexone appears to work differently than it does at standard doses. Rather than simply blocking opioid receptors full-time (as it does at 50 mg for addiction treatment), the brief blockade at low doses is thought to trigger an increase in the body’s own endorphin production and modulate immune system activity. This is why it shows up in treatment plans for such a wide range of inflammatory and pain conditions.
Side Effects During the First Few Weeks
Most side effects are mild and tend to fade as your body adjusts. The most commonly reported issue is vivid dreams or sleep disturbance during the first week or two, which is one reason doctors start at a low dose and gradually increase. Some people experience mild headaches, nausea, or temporary anxiety early on. The gradual titration schedule exists specifically to minimize these effects.
Who Should Not Take LDN
LDN is not safe to use if you are currently taking opioid medications, including prescription painkillers. Because naltrexone blocks opioid receptors, combining it with opioids can trigger sudden withdrawal symptoms. You need to be fully off opioid medications before starting LDN, and your doctor will want to confirm an adequate washout period.
If you’re taking tamoxifen for breast cancer treatment, discuss the potential interaction with your oncologist, as it’s unclear whether LDN affects how tamoxifen works. LDN may also interact with other medications, so a full medication review with your prescriber is an important step before starting.
Steps to Get Started
The practical path is straightforward once you know the process. First, identify a prescriber, whether that’s your current doctor, an integrative medicine provider, or a telehealth clinic. Second, discuss your health history and current medications to make sure LDN is appropriate. Third, get the prescription sent to a compounding pharmacy, either one nearby or a mail-order service. Most people have their medication in hand within a few days to a week of the initial appointment.