--- title: Low-dose naltrexone for PMDD: dosage and safety guide description: Low dose naltrexone for PMDD has no fixed dosage from trials yet; here's why, how it's typically dosed off-label, and when a doctor's input matters. url: https://niyora.com/treatments/ldn-dosage/ --- - [Niyora](https://niyora.com/) - [Treatments](https://niyora.com/treatments/) - Low-dose naltrexone for PMDD: how much and when Treatments # Low-dose naltrexone for PMDD: how much and when - No trial has set a standard dose, schedule or frequency for naltrexone in PMS or PMDD. - Off-label dosing for other conditions is borrowed, not tested for premenstrual symptoms. - Trying it is a decision for a doctor, not a dose to pick yourself. Updated 14 October 2026 Niyora editorial No good evidence yet Strength of evidence None No good trials have tested it yet. - None - Limited - Mixed - Moderate - Strong ## At a glance - No randomized trial has set a naltrexone dose for PMS or PMDD; current off-label dosing is borrowed from other conditions. - Naltrexone is usually taken daily for other off-label uses, but no trial compares daily versus luteal-phase-only dosing for premenstrual symptoms. - Signs of too much naltrexone include nausea, dizziness, stomach pain and liver strain, and it can interact dangerously with opioid medication. - PMS and PMDD share the same evidence gap for naltrexone dosing, since neither has a dedicated trial. - Track two months of daily symptoms before an appointment so a doctor has specifics to work with, not a vague sense of the days before her period. ## Strength of evidence No good evidence yet - None - Limited - Mixed - Moderate - Strong None of the randomized trials behind current PMS and PMDD treatment test naltrexone, so no dose, timing or effect size has trial evidence behind it. Everything about low-dose naltrexone for premenstrual symptoms comes from how it's used in other off-label conditions, not from cycle-specific research. ## What is the usual dose of low-dose naltrexone for PMDD? **No dose of low-dose naltrexone has been set by a clinical trial for PMS or PMDD.** Naltrexone is an opioid receptor blocker. At the dose used for opioid or alcohol dependence, it stops opioids from working. At a much smaller dose, it's prescribed off-label for conditions like fibromyalgia, Crohn's disease and some chronic pain syndromes, usually starting low and increasing slowly over weeks. For PMS and PMDD, the trial evidence looks different. Treatments tested in randomized trials for premenstrual symptoms include: - Certain birth control pills - Low-dose SSRIs like fluoxetine and sertraline - A few hormone-based drugs Naltrexone doesn't appear in that evidence base. That means any dose used for PMDD today is borrowed from how it's dosed for other conditions, not from a trial that measured its effect on premenstrual mood or physical symptoms. If a doctor is willing to try LDN for PMDD, they'll usually start at the low end used for other off-label conditions and watch how you respond over a cycle or two, rather than following a PMDD-specific protocol, because one doesn't exist yet. ## When should you take it, and can you take it every day? **Naltrexone's timing for premenstrual symptoms hasn't been tested**, but other treatments offer a useful comparison. | Treatment | Dosing tested in trials | Tested this way for naltrexone? | | --- | --- | --- | | Drospirenone/ethinyl estradiol pill | Daily, continuous (24 active days, 4 inactive) | No | | Low-dose fluoxetine | Luteal phase only, about a week before the period | No | | Low-dose sertraline | Luteal-only, continuous, or started at symptom onset | No | | Low-dose naltrexone | Not tested in a published premenstrual trial | Not applicable | A small trial found low-dose fluoxetine taken only in the days before a period reduced emotional PMS symptoms, with 10mg a day showing the most consistent effect (Psychoneuroendocrinology, 2023). A larger trial of low-dose sertraline compared luteal-only, continuous, and symptom-onset dosing, and found all three worked, with luteal-only dosing effective across two cycles (The Journal of Clinical Psychiatry, 2006). No equivalent comparison exists for naltrexone. In practice, naltrexone is usually taken once daily, often at night, for the other conditions it's prescribed for off-label. Whether that daily pattern or a luteal-phase-only one works better for premenstrual symptoms is unknown. If you start LDN for PMDD, your doctor decides the schedule, possibly based on how your other premenstrual treatments have been timed. ## What happens if you take too much? **Taking more naltrexone than prescribed isn't a dose to self-adjust.** Signs that a dose may be too high include: - Nausea or vomiting - Stomach pain - Dizziness or unusual tiredness - Headache that doesn't ease - Yellowing of the skin or eyes, which can signal liver strain Naltrexone also blocks opioid receptors, which matters if you're taking opioid pain medication for another reason, or might need one for surgery or an injury. Naltrexone can make those medications stop working, or cause sudden withdrawal symptoms if you've been taking opioids regularly. If you think you've taken too much, or you're not sure what dose you're meant to be on, call your doctor or a pharmacist before your next dose. Don't guess. If you feel seriously unwell, treat it as an urgent medical issue and go to urgent care or an emergency room. When to see a doctor Never adjust an LDN dose based on how a day feels. Call your prescriber first, before changing anything. ## Does the dose differ for PMS and PMDD? No naltrexone dose has been set for PMS specifically, and none has been set for PMDD specifically either. **The gap in evidence is the same whichever pattern fits you.** What differs is the diagnosis, not the drug. PMS covers physical or emotional symptoms in the one to two weeks before a period that ease once it starts. PMDD is a specific diagnosis, confirmed by daily symptom tracking over at least two cycles, with at least five symptoms including a mood symptom. If you're not sure which fits, [what is PMS](https://niyora.com/premenstrual-syndrome/) walks through the difference. Either way, a doctor deciding whether to try LDN with you will weigh the same limited off-label evidence, not a dose tailored to one diagnosis over the other. ## What else should you know before trying LDN for PMDD? **Niyora is a PMS and PMDD support app.** Before you start LDN, a few things make the conversation with a doctor more useful than a dose number alone: - Track your symptoms daily for at least one full cycle, ideally two, using something like the [DRSP chart](https://niyora.com/tools/drsp-chart/), so you have real data instead of a general impression. - Ask what the evidence on effectiveness actually looks like, not just the dose, at [low-dose naltrexone for PMDD](https://niyora.com/treatments/ldn-for-pmdd/) or [for PMS](https://niyora.com/treatments/ldn-for-pms/), depending on which pattern fits you. - Bring that tracking and your questions to the appointment rather than starting a dose on your own. If you're waiting on an appointment and want somewhere to put what's happening this cycle, Niyora's Moon lets you write down what happened, see it from another angle, and draft what you want to say, so two months of notes turn into something specific instead of a vague sense that something's off. ## When does LDN dosing need a doctor's input? Don't start or change a naltrexone dose on your own. If this takes a week of every month, affects your relationships or work, or you have thoughts of hurting yourself, see a GP, gynecologist, or [PMDD specialist](https://niyora.com/care/pmdd-specialist/), and bring two months of daily symptom notes. If naltrexone is already part of your treatment and you notice new nausea, stomach pain, dizziness or yellowing skin, call before your next dose rather than stopping or adjusting it yourself. This applies whether you're on LDN already or only considering it, since the research gap means a doctor's judgment matters more here than it would for a better-studied drug. ## Questions people ask Is there a standard low-dose naltrexone dose for PMDD? + No. No published randomized trial has set a standard naltrexone dose for PMS or PMDD. Doctors who prescribe low-dose naltrexone off-label for other conditions typically start low and adjust based on response, but that approach hasn't been tested specifically for premenstrual symptoms. Can you take low-dose naltrexone every day for PMDD? + Low-dose naltrexone is usually taken daily for other off-label uses, but that schedule hasn't been tested for PMDD specifically. Whether daily dosing or a luteal-phase-only schedule works better for premenstrual symptoms is something only a doctor can help you work through, since no trial compares them for naltrexone. What happens if you take too much naltrexone? + Too much naltrexone can cause nausea, dizziness, headache and liver strain, and it can be dangerous if you're also taking opioid pain medication. If you've taken more than prescribed, or feel seriously unwell, call your doctor or go to urgent care. Does naltrexone dosing differ for PMS versus PMDD? + No naltrexone dose has been established for either PMS or PMDD specifically. Both conditions sit outside the published trials behind current premenstrual treatment, so the dosing question is the same unresolved gap, and only a doctor can help you weigh the off-label evidence either way. Where can I find naltrexone dosing guidance for PMDD? + There isn't a published guideline for naltrexone dosing in PMDD yet. A doctor experienced with PMDD, such as one found through a PMDD specialist referral, can weigh the off-label evidence from other conditions against your own health history. ## Sources - 1. [Efficacy of a new low-dose oral contraceptive with drospirenone in premenstrual dysphoric disorder](https://doi.org/10.1097/01.aog.0000175834.77215.2e), Obstetrics and gynecology, 2005 - 2. [Low doses of fluoxetine for the treatment of emotional premenstrual syndrome: a randomized double-blind, placebo-controlled, pilot study](https://doi.org/10.1016/j.psyneuen.2023.106360), Psychoneuroendocrinology, 2023 - 3. [Low-dose sertraline in the treatment of moderate-to-severe premenstrual syndrome: efficacy of 3 dosing strategies](https://doi.org/10.4088/jcp.v67n1020), The Journal of clinical psychiatry, 2006 Ask AI about this page Copy prompt ChatGPT ↗ Claude ↗ Perplexity ↗ Google AI Mode ↗ Grok ↗ On this page - [What is the usual dose of low-dose naltrexone for PMDD?](#what-is-the-usual-dose-of-low-dose-naltrexone-for-pmdd) - [When should you take it, and can you take it every day?](#when-should-you-take-it-and-can-you-take-it-every-day) - [What happens if you take too much?](#what-happens-if-you-take-too-much) - [Does the dose differ for PMS and PMDD?](#does-the-dose-differ-for-pms-and-pmdd) - [What else should you know before trying LDN for PMDD?](#what-else-should-you-know-before-trying-ldn-for-pmdd) - [When does LDN dosing need a doctor's input?](#when-does-ldn-dosing-need-a-doctor-s-input) - [Questions](#faq) Niyora PMS & PMDD support For the hard moment before your period. Private, no account. [Get it on iPhone](https://apps.apple.com/app/niyora-pms-emotions/id6764561688) ## Keep reading Treatment Low-dose naltrexone for PMS: does it work? Treatment Low-dose naltrexone for PMDD: does it work? Treatment PMS treatment: what actually helps Condition What is PMS? Premenstrual syndrome, explained Care guide Finding a PMDD specialist Guide All 26 research findings