Low Dose Naltrexone and Fertility

What to Know If You Are Trying to Conceive

When pregnancy does not happen as easily as expected, it can leave people searching for answers that do not always show up clearly on lab work. Cycles may appear regular. Hormone levels may fall within normal ranges. Imaging may come back reassuring. And yet conception still feels out of reach.

In these moments, it is common to start hearing about therapies that are not part of conventional fertility conversations. Low dose naltrexone, often called LDN, is one of those options. Many people encounter it through online forums, reproductive immunology discussions, or conversations with others navigating unexplained infertility or complex fertility journeys.

More often than not, I enter the picture as a new perspective in someone’s long and deeply personal journey toward becoming a parent. In some cases, I am the first person who has ever introduced the idea of low dose naltrexone. The questions I hear are simple, honest, and deeply understandable. What is low dose naltrexone, and could it have a place in my fertility journey?

What is low dose naltrexone

Naltrexone is a medication that has been used for decades at higher doses to treat opioid and alcohol dependence. Low dose naltrexone uses a much smaller amount, typically between 0.5 and 4.5 milligrams per day, and works in a very different way.

At low doses, naltrexone temporarily blocks opioid receptors for a short period of time. This brief interruption signals the body to increase its own production of endorphins and enkephalins. These naturally occurring compounds are involved in immune regulation, inflammation balance, pain perception, stress response, and communication between the brain and hormonal systems.

Rather than forcing a specific hormonal outcome, LDN works by influencing how the body regulates itself. This is why it often comes up in conversations about complex or unexplained fertility challenges.

So what's the scoop with Low Dose Naltrexone and Fertility?

Low dose naltrexone is not a fertility drug in the conventional sense. It does not stimulate ovulation, replace progesterone, or override the body’s natural hormone production.

Instead, its potential role lies in supporting communication between the nervous system, immune system, and endocrine system. By increasing endogenous endorphins, LDN may help regulate stress signaling, immune balance, and hormonal feedback loops that are essential for ovulation, implantation, and early pregnancy.

For some people, this broader regulatory effect is what makes LDN appealing, especially when standard fertility treatments have not addressed the whole picture.

Where inflammation and immune balance come into the conversation

Inflammation can influence fertility in ways that are not always obvious on routine testing. It may affect egg quality, ovulation consistency, thyroid signaling, endometrial receptivity, implantation, or early placental development.

In my practice, I most often consider LDN as part of fertility support when there are additional factors such as endometriosis, PCOS with inflammatory features, Hashimoto’s thyroiditis, chronic gastrointestinal inflammation, or a history suggestive of immune mediated implantation challenges or pregnancy loss.

In these cases, LDN is not used to suppress the immune system, but rather to support regulation and balance.

What the research tells us about Low Dose Naltrexone and Fertility

The strongest body of research on low dose naltrexone exists in the context of autoimmune and chronic inflammatory conditions rather than fertility specifically. In these settings, LDN has been shown to influence immune signaling by reducing pro inflammatory cytokines and supporting regulatory immune pathways, without suppressing immune function outright.¹² These mechanisms are relevant because balanced immune regulation plays an important role in implantation and early pregnancy.

This distinction is especially meaningful for individuals who are already managing autoimmune conditions or who feel hesitant about medications that suppress the immune system rather than support balance and regulation.

Data specific to fertility and pregnancy outcomes remain limited. Much of LDN’s use in reproductive care is informed by reproductive immunology literature, specialist clinical experience, and patient centered outcomes rather than large scale pharmaceutical trials.³ This reflects how LDN is often used in integrative and specialty settings, where clinical decision making is guided by physiology, safety data, and observed response rather than condition specific drug approval.

This gap in fertility specific research does not indicate a lack of scientific rationale. Instead, it highlights a broader reality in fertility medicine, where the complexity of immune and hormonal interactions often outpaces large scale research funding and trial design. As a result, carefully selected off label therapies like low dose naltrexone are sometimes considered when conventional approaches do not fully address the underlying physiology.

What I observe clinically

In my clinical experience, low dose naltrexone is generally very well tolerated, particularly when introduced gradually.

I typically start at a low dose and increase slowly over time, allowing the body to adjust and helping us identify the most supportive dose for each individual. This approach is especially important for patients who are sensitive to medications or who have already been through extensive fertility treatment.

Some people notice changes in sleep, energy, pain, digestion, or overall inflammation before any fertility specific outcomes shift. Others describe feeling more regulated, less reactive, or more resilient. These responses often provide valuable insight into how the body is responding to treatment.

Is LDN safe when trying to conceive

Low dose naltrexone is generally considered safe during the preconception period and does not interfere with ovulation or fertility medications. Common side effects are usually mild and may include vivid dreams, temporary sleep changes, headache, or nausea. LDN cannot be used alongside opioid based pain medications.

Use during pregnancy is individualized. Some fertility and reproductive immunology specialists continue LDN into early pregnancy for patients with autoimmune or inflammatory conditions, while others discontinue it after a positive pregnancy test. This decision is always made collaboratively and based on the individual’s history and care plan.

A whole person approach to fertility support

Fertility care is not just about achieving pregnancy. It is about supporting the whole person and the internal environment in which pregnancy begins.

Low dose naltrexone is not appropriate for everyone. For some individuals, particularly those navigating fertility alongside immune or inflammatory complexity, it can be a gentle and well tolerated part of a comprehensive, integrative support plan.

If you are trying to conceive, feeling stuck, and wondering whether there may be more going on beneath the surface, this is a conversation worth exploring with a knowledgeable care team.

Curious whether low dose naltrexone could be part of your fertility care plan? Let’s talk. Book a consultation to explore integrative fertility support tailored to your body and goals.

References

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2. Brown N, Panksepp J. Low dose naltrexone for disease prevention and quality of life. Med Hypotheses. 2009;72(3):333–337. doi:10.1016/j.mehy.2008.09.035

3. Smith JP, Stock H, Bingaman S, et al. Low dose naltrexone therapy improves active Crohn’s disease. Am J Gastroenterol. 2007;102(4):820–828. doi:10.1111/j.1572-0241.2007.01110.x

4. Smith JP, Field D, Bingaman SI, Evans R, Mauger DT. Safety and tolerability of low dose naltrexone therapy in children with moderate to severe Crohn’s disease. J Clin Gastroenterol. 2013;47(4):339–345. doi:10.1097/MCG.0b013e3182702f2b

5. Zagon IS, McLaughlin PJ. Endogenous opioid systems regulate cell proliferation in the developing rat brain. Brain Res. 1987;412(1):68–72. doi:10.1016/0006-8993(87)91424-2

6. Zagon IS, McLaughlin PJ. Opioid antagonist modulation of cell proliferation in human neuroblastoma. Brain Res. 1984;293(2):295–302. doi:10.1016/0006-8993(84)91458-4

7. Li Q, Wang X, Lu Z, et al. Regulatory T cells and reproductive immune tolerance. Front Immunol. 2021;12:689607. doi:10.3389/fimmu.2021.689607

8. Robertson SA, Chin PY, Glynn DJ, Thompson JG. Peri-conceptual cytokines setting the trajectory for embryo implantation, pregnancy, and beyond. Am J Reprod Immunol. 2011;66(s1):2–10. doi:10.1111/j.1600-0897.2011.01039.x