The main thing to avoid while taking low dose naltrexone is opioids. Naltrexone blocks opioid receptors, so opioid pain medicines and opioid-containing over-the-counter products may not work as expected, and in someone physically dependent on opioids it can cause sudden, severe withdrawal. Everything else on the avoid list follows from that one fact.
Low Dose Naltrexone (LDN) is a compounded, prescription-only preparation of naltrexone hydrochloride, made at a small fraction of the drug's FDA-approved 50 mg strength. Bayview Pharmacy prepares it as capsules, tablets, and an oral liquid to a prescriber's order. Naltrexone is FDA-approved only at 50 mg for alcohol use disorder and opioid use disorder, so every use at low doses is off-label, and the compounded preparation itself is not FDA-approved.
What to avoid when taking low dose naltrexone
Opioid pain medications
Naltrexone is an opioid antagonist. It competes for the same receptors that oxycodone, hydrocodone, morphine, codeine, tramadol, and similar medicines act on. Two things can happen as a result. If you are physically dependent on opioids, starting naltrexone can precipitate withdrawal, which can come on quickly and be severe. If you are not dependent but need opioid analgesia, that analgesia may be blunted or absent.
Trying to overcome the blockade by taking more opioid is dangerous and can be fatal. Do not do it. If pain is not controlled, that is a call to your prescriber, not a reason to escalate an opioid dose on your own.
Surgery, dental work, and emergency care
Anyone who may need opioid analgesia should tell every clinician involved that they take naltrexone. That means the surgeon, the anesthesiologist, the dentist, and anyone treating you in an emergency department, and it means telling them in advance where that is possible. Published guidance on how long to stop naltrexone before a procedure varies considerably, and no fixed interval has been established for low doses. That decision belongs to your prescriber and the clinician performing the procedure. Carrying a card or a medical ID noting that you take naltrexone is a reasonable precaution.
Sensitivity to opioids can be increased after naltrexone is stopped, another reason any stop, restart, or perioperative plan should be coordinated rather than improvised.
Opioid-containing products you might not think of
Some cough and cold preparations contain codeine or hydrocodone. Some antidiarrheal medicines contain opioid or opioid-related ingredients, including loperamide and diphenoxylate. These may not work as expected while you are taking naltrexone. Read labels, and ask a pharmacist before buying anything for a cough or for diarrhea.
Alcohol
Naltrexone does not cause the violent reaction that disulfiram does, and it does not prevent intoxication. It is not contraindicated with alcohol the way disulfiram is. That said, this information comes from studies at the 50 mg dose; alcohol has not been studied specifically at low doses. Whether drinking is advisable for you, given your other medicines and conditions, is a question for your prescriber.
Other medications and timing
Beyond opioids and opioid-containing over-the-counter products, the documented interactions are narrow. The labeling for standard-dose naltrexone notes lethargy and sleepiness reported when it was combined with thioridazine. There is no published low-dose-specific interaction data for antidepressants, thyroid medication, stimulants, or biologics.
On timing: bedtime dosing is the convention, and it came from a theory about overnight receptor blockade that has not been confirmed. Reviews state plainly that no clear evidence shows nighttime dosing works better than daytime dosing, and because disturbed sleep is among the more commonly reported effects, some prescribers move the dose to the morning. That is a conversation to have, not a change to make on your own. Bring a full list of your medicines and supplements to your prescriber and pharmacist.
Low dose naltrexone side effects
Tolerability is the best-supported part of the LDN evidence base. Across published studies at these doses, reviews consistently describe naltrexone at roughly 0.5 to 6 mg as well tolerated.
The effects reported more often on LDN than on placebo in pooled trial data are vivid or abnormal dreams and nausea. Other commonly mentioned effects include trouble sleeping, headache, dizziness, fatigue, and stomach upset. Small studies commonly describe these as appearing early in therapy and as transient, though that description comes largely from studies without a comparison group.
Context matters here. In the two largest randomized trials, the overall rate of side effects was roughly the same on naltrexone as on placebo, 84% versus 86% in one and 69% versus 72% in the other. That means most reported effects in those studies were not attributable to the medication. It does not mean nobody has trouble with it. Some participants did stop because of side effects. Report anything that concerns you.
Get medical care right away for signs of a serious allergic reaction (rash, swelling of the face or throat, trouble breathing), for symptoms of opioid withdrawal (agitation, sweating, cramping, vomiting, diarrhea), or for yellowing of the skin or eyes, dark urine, or severe abdominal pain.
Symptoms of too much low dose naltrexone
No published threshold defines an overdose at these strengths. What the literature describes is that reported effects tend to be dose-related in a general way, so vivid dreams, nausea, headache, or grogginess appearing or worsening after a dose increase is the pattern prescribers usually react to when they slow a titration or step back down.
Do not adjust your dose yourself. Call your prescriber, and call a poison control center or seek care if a much larger amount was taken. Do not attempt to make a smaller dose by splitting or dissolving a 50 mg tablet; that tablet is roughly ten to thirty times a typical low dose, splitting cannot deliver that accuracy, and there is no published stability data for home-prepared naltrexone solutions.
Long term side effects of low dose naltrexone
Honest answer: there is limited long-term controlled data at low doses. Most published LDN research consists of case reports and small studies without a comparison group, and the randomized trials that exist have generally run weeks to months rather than years. A 2026 fibromyalgia trial published in the European Journal of Pain ran 12 months, which is at the long end of what has been studied.
Serious liver injury has been reported with naltrexone at the 50 mg dose. Reviews report that clinically significant liver enzyme changes are uncommon at low doses. Whether to monitor liver tests, and how often, is your prescriber's decision. Tell them if you have liver problems. There is also no low-dose-specific safety data in pregnancy or breastfeeding; the labeling for standard-dose naltrexone states there are no adequate and well-controlled studies in pregnant women and that it is not known whether naltrexone passes into human milk.
Can I just stop taking low dose naltrexone?
Naltrexone is not a controlled substance, has low potential for misuse, and the literature does not describe a withdrawal syndrome when it is stopped. No physical dependence on naltrexone is described. So in the narrow pharmacological sense, there is nothing to taper off.
That is not the same as stopping without telling anyone. Sensitivity to opioids can be increased after stopping, which matters if opioid analgesia is on the horizon. And your prescriber needs to know you came off, especially if a side effect drove it and could be managed by moving the dose or changing the strength or form.
Side effects of stopping low dose naltrexone
The published literature does not describe a discontinuation or withdrawal syndrome for naltrexone. What people typically notice, if anything, is the return of whatever they were taking it for. Any change to your regimen should go through the prescriber who wrote it.
What the literature reports about low dose naltrexone benefits
This deserves a straight answer. The most recent independent review, published in Advances in Therapy in 2026, examined 105 studies of LDN, of which only 15 were randomized controlled trials, and concluded that early positive findings from uncontrolled studies were rarely replicated in placebo-controlled trials and that current evidence does not support routine clinical use. In fibromyalgia, two adequately powered randomized trials, one of them the FIBRO-LDN trial in The Lancet Rheumatology in 2024, did not find a significant difference from placebo on their main outcomes. A 2018 Cochrane review of Crohn's disease found insufficient evidence to allow any firm conclusions. For ulcerative colitis, long COVID, ME/CFS, and complex regional pain syndrome, there is no published randomized controlled trial.
Two things are worth knowing when you read LDN claims elsewhere. The striking response rates that circulate online almost all come from studies with no placebo group, and in trials that did include one, 18 to 40% of people receiving placebo also reported improvement. And doses are frequently confused, with research conducted at 50 mg or higher cited as though it were LDN evidence. We make no claim that LDN is effective for any condition.
Strength comparison and approval status
These are the same molecule at very different amounts. The table is educational only and is not a dosing recommendation.
| Preparation | Typical amount | Supply | Status |
|---|---|---|---|
| Standard-dose naltrexone | 50 mg daily | Manufactured tablet, injection | FDA-approved |
| Low dose naltrexone (LDN) | 0.5 to 6 mg | Compounded to order | Off-label, not FDA-approved |
| Ultra-low-dose naltrexone | Below 1 mg | Compounded, research only | Off-label, no approved product |
The 50 mg product is approved for alcohol use disorder and opioid use disorder and also comes as a monthly injection, while microgram amounts appear only in small research settings and are not a routine Bayview preparation.
Because naltrexone is manufactured only as a 50 mg tablet, there is no mass-produced 1.5 mg or 4.5 mg product to dispense. That is the entire reason LDN comes from a compounding pharmacy, not because a compounded version is different or better.
What Bayview compounds for this
On a prescriber's order, Bayview prepares low dose naltrexone as capsules in 1, 2, 4, 4.5, 5, 6, and 9 mg, as compounded tablets in 1.5, 3, and 4.5 mg, and as a 1 mg/mL oral liquid supplied as a suspension or a flavored solution for patients who cannot swallow a solid dose or who need sub-milligram titration steps. Other strengths are compounded to order, in small batches under USP 795 non-sterile compounding standards. If capsule fillers are a concern, ask our pharmacist; we can tell you exactly what is in your preparation. A starting cash price of $100 covers 90 capsules, and LDN is generally not billed through insurance, which we cover in do compounding pharmacies take insurance. More on sourcing the preparation is in our guide to using a low dose naltrexone compounding pharmacy, and the full catalog is at compounded medications.
Talk to your prescriber
Dose, strength, form, schedule, and whether LDN is appropriate at all are your prescriber's decisions, not ours and not something to work out from an article. If you have questions about what to avoid, about a side effect, or about switching between a capsule, a tablet, and a liquid, raise them with your prescriber and ask them to send a prescription to Bayview. Our pharmacists can answer questions about your prescription, and we fill and ship to the states where Bayview is licensed, listed on our FAQ.
Frequently asked questions
How should I store LDN?
Store capsules and tablets at room temperature unless the prescription label says otherwise. Keep the container tightly closed, away from excess heat, moisture, and direct light, a bathroom cabinet is a poor choice because of humidity. If you have been prescribed a liquid, check your label to see whether it needs refrigeration. Keep all medication out of reach of children and pets, and do not use any preparation past the beyond-use date on the label.
How long does it take to notice a response?
LDN does not produce an immediate effect. Patient-facing references commonly suggest allowing up to eight to ten weeks, though no clinical trial has established a reliable time-to-response figure, and published studies describe it inconsistently. Response can vary with the individual, the dose, and the overall treatment plan. Follow your prescriber’s instructions and check in as directed rather than stopping early on your own.
What side effects can happen with LDN?
LDN is generally well tolerated at these doses. The effects reported most often, and more often than with placebo in pooled trial data, are vivid or unusual dreams and nausea. Others reported include sleep disturbance, headache, dizziness, stomach upset, and fatigue. Worth knowing: in the two largest randomized trials the overall rate of side effects was about the same on naltrexone as on placebo, so many reported effects were not attributable to the medication. Contact your prescriber if anything is bothersome, persistent, or unexpected.
Can I take LDN if I use opioid pain medication?
You should not take LDN with opioid medications unless your prescriber specifically determines it is safe. Naltrexone blocks opioid receptors, which may reduce the effect of opioid pain medications and may trigger withdrawal in someone who is physically dependent on opioids. Tell your provider and pharmacist about all medications you take.
Why is LDN compounded?
Naltrexone is commercially manufactured only as a 50 mg tablet, so the low doses commonly used, such as 1.5 mg, 3 mg, or 4.5 mg, are not available as a standard product. Compounding allows a licensed pharmacy to prepare naltrexone at the exact strength your provider prescribes, and in the form that suits you: a capsule, a tablet, or an oral liquid. Please do not attempt to split or dissolve a 50 mg tablet at home, that cannot deliver an accurate low dose.
How do I take LDN?
Take LDN exactly as prescribed by your provider, whether it is a capsule, a tablet, or an oral liquid. It is often taken once daily, sometimes at bedtime, but your directions may be different. If you have been prescribed the liquid, measure each dose with the oral syringe provided rather than a household spoon. Do not change your dose, timing, or frequency unless your prescriber tells you to.
What strengths are available?
Bayview Pharmacy prepares LDN in the strength and form your prescriber orders. Compounded tablets, pressed in our own pharmacy, are available in 1.5, 3 and 4.5 mg. Capsules cover the strengths in between and the very low starting doses, from 0.125 mg up to 9 mg. An oral liquid is also available, which allows very small dose steps for patients who need them or who cannot swallow a solid dose. Other strengths can be compounded to order. Many providers start at a lower strength and adjust gradually.
Is Low Dose Naltrexone FDA-approved?
Naltrexone is FDA-approved at standard doses for opioid and alcohol use disorders. Low Dose Naltrexone is prescribed off-label and compounded at lower strengths, so it is not FDA-approved for these uses. Your prescriber determines whether it is appropriate for your treatment plan.
What is Low Dose Naltrexone?
Low Dose Naltrexone, often called LDN, is naltrexone prepared in much smaller doses than the commercially available 50 mg tablet. Because these low strengths are not sold as a standard manufactured product, they are commonly prepared by a compounding pharmacy with a prescription.
What should I avoid when taking low dose naltrexone?
Opioids, above all. Naltrexone blocks opioid receptors, so opioid pain medicines may not work as expected, and in someone physically dependent on opioids it can cause sudden, severe withdrawal. Avoid opioid-containing cough, cold, and antidiarrheal products for the same reason, and never take extra opioid to overcome the blockade. Tell any surgeon, dentist, or emergency clinician that you take naltrexone, in advance where possible.
Can I drink alcohol on low dose naltrexone?
Naltrexone does not cause the violent reaction that disulfiram does, and it does not prevent intoxication, so it is not contraindicated with alcohol in that way. That information comes from studies at the FDA-approved 50 mg dose; alcohol has not been studied specifically at low doses. Whether drinking is advisable for you, given your other medicines and conditions, is a question for your prescriber.
Can I just stop taking low dose naltrexone?
Naltrexone is not a controlled substance and the published literature does not describe a withdrawal syndrome when it is stopped, so no physical dependence is described. Even so, tell your prescriber before you stop. Sensitivity to opioids can be increased afterward, which matters if opioid analgesia may be needed, and a side effect that prompted stopping might be handled by changing the dose, strength, or form.
What are the most common low dose naltrexone side effects?
The effects reported more often than placebo in pooled trial data are vivid or abnormal dreams and nausea. Trouble sleeping, headache, dizziness, fatigue, and stomach upset are also commonly mentioned, and small studies often describe them as appearing early and as transient. In the two largest randomized trials the overall side-effect rate was about the same on naltrexone as on placebo. Report anything that concerns you.
Are there long term side effects of low dose naltrexone?
There is limited long-term controlled data at low doses. Most published LDN research is case reports and small uncontrolled studies, and the randomized trials that exist have generally run weeks to months. Serious liver injury has been reported at the 50 mg dose; reviews report that clinically significant liver enzyme changes are uncommon at low doses. Whether to monitor liver tests is your prescriber's decision.
Do I need to stop LDN before surgery?
Tell the surgeon, anesthesiologist, or dentist that you take low-dose naltrexone, in advance wherever possible, because opioid pain relief may not work normally. Published guidance on how long to stop beforehand varies considerably, and no fixed interval has been established for low doses. Do not decide on your own; your prescriber and the clinician performing the procedure make that call together.
Why does low dose naltrexone have to be compounded?
Naltrexone is commercially manufactured only as a 50 mg tablet. There is no mass-produced 1.5 mg or 4.5 mg product, so low strengths have to be prepared by a compounding pharmacy. That is the only reason it is compounded, not because a compounded version is different or better. Do not try to split or dissolve a 50 mg tablet at home; the accuracy is not there and no stability data supports it.
What does low dose naltrexone cost at Bayview?
Cash pricing starts at $100 for 90 capsules, with the exact price depending on the strength, form, and quantity your prescriber orders. Compounded preparations are generally not billed through insurance because they do not carry the national drug codes insurers adjudicate against. Contact the pharmacy to confirm current pricing before assuming a figure for an unusual strength or quantity.
What Bayview compounds for this
Important: Compounded medications are prepared to a prescriber's order for an individual patient. They are not FDA-approved, and the FDA has not evaluated them for safety, effectiveness, or manufacturing quality. This article is educational and is not a substitute for advice from your prescriber or pharmacist.
This preparation contains a controlled substance. Controlled-substance prescriptions carry refill limits, must be e-prescribed, and can only be shipped to states where Bayview holds the required licensure.
Uses discussed here may be off-label, meaning they are not part of any FDA-approved labeling. Off-label use is a decision for you and your prescriber, based on the available evidence.
Veterinary preparations are compounded to a veterinarian's order for a specific animal and are not FDA-approved animal drugs. Never give a compounded human medication to an animal without veterinary direction.
Compounded prescriptions are paid for directly rather than billed through insurance. Most are HSA/FSA-eligible, and many patients submit the receipt to their plan for possible reimbursement. Pricing depends on the strength, dose form and quantity your prescriber orders. Read more about cost and insurance.
Low dose naltrexone at Bayview starts at $100 cash for 90 capsules, with the final price depending on the strength, form, and quantity on the prescription. Compounded preparations are generally not billed through insurance, since they are prepared for an individual patient and do not carry the national drug codes insurers adjudicate against. Patients typically pay cash and may be able to submit a receipt to an HSA or FSA.
Bayview Pharmacy is a compounding pharmacy in Warwick, Rhode Island, licensed to fill and ship compounded prescriptions for patients in Rhode Island, Massachusetts, Connecticut, New Jersey, New Hampshire, Florida, Maine and Pennsylvania. Prescriptions for New York patients are filled on a limited basis, and controlled substances are not shipped to New York addresses. See every state we ship to.
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