Hair Loss, Hormones, and Hidden Causes: An Integrative Medicine Approach

Why Your Hair Might Be Telling You Something Important

Hair loss is one of those complaints that conventional medicine often dismisses as "just cosmetic" or "just genetics." But after two decades of practicing integrative and functional medicine, I've learned that your hair is often a window into what's happening deeper in your body.

When patients come to me with thinning hair, I don't just see a cosmetic concern—I see an opportunity to investigate what's really going on.

The Problem with "It's Just Genetic"

Yes, genetics matter. But here's what I tell my patients: genetics load the gun, but environment pulls the trigger.

I've seen countless patients who were told their hair loss was simply androgenetic alopecia—take some minoxidil and accept it. But when we dig deeper, we often find thyroid dysfunction, nutrient deficiencies, gut issues, or hormonal imbalances that, once addressed, change the trajectory entirely.

The functional medicine approach doesn't dismiss genetics. It asks: what's activating these genetic tendencies, and can we do something about it?

Root Causes I Look For

Thyroid Dysfunction

This is probably the most commonly missed contributor to hair loss. And here's the frustrating part—standard thyroid testing often misses it.

A TSH of 3.5 might be "normal" on a lab report, but it's not optimal. I check the full panel: TSH, free T3, free T4, reverse T3, and thyroid antibodies. Many patients with "normal" thyroid tests actually have subclinical hypothyroidism or Hashimoto's thyroiditis that's affecting their hair.

Nutrient Deficiencies

Hair is what I call a "luxury tissue." When your body is short on resources, it prioritizes vital organs over hair follicles. The nutrients I most commonly find deficient in hair loss patients include:

• Iron (even when ferritin is "low normal")
• Zinc
• Vitamin D
• B vitamins, especially biotin and B12
• Protein (yes, even in people who think they eat enough)

A 2019 study found that 38% of women complaining of hair loss had biotin deficiency, with another 49% having suboptimal levels. That's nearly 90% of patients who might benefit from a simple intervention.

Hormonal Imbalances

In women, I look at the full hormonal picture—not just estrogen and progesterone, but testosterone, DHEA, and their metabolites. Conditions like PCOS often show up as hair thinning years before other symptoms become obvious.

In men, the issue is often excessive conversion of testosterone to DHT (dihydrotestosterone), which shrinks hair follicles over time. But the solution isn't always blocking DHT with medications—sometimes it's addressing the inflammation and insulin resistance that drive this conversion.

Gut Health

This one surprises patients. What does your gut have to do with your hair?

Everything, as it turns out.

Poor gut function means poor nutrient absorption. Intestinal permeability ("leaky gut") creates systemic inflammation. Gut dysbiosis can even affect hormone metabolism. I've seen patients whose hair started regrowing after we addressed SIBO or food sensitivities—without any hair-specific treatment at all.

Chronic Inflammation and Immune Dysregulation

This is where conditions like alopecia areata come in, but even pattern hair loss has an inflammatory component. Research shows chronic microinflammation around hair follicles contributes to follicular miniaturization.

This is also where some of the more innovative treatments come into play.

The Role of Low-Dose Naltrexone (LDN)

I've been prescribing low-dose naltrexone for over two decades, primarily for chronic pain, autoimmune conditions, and complex inflammatory disorders. But its immune-modulating effects have implications for hair loss as well—particularly in cases driven by autoimmune processes or systemic inflammation.

How LDN Works

At standard doses (50mg), naltrexone blocks opioid receptors to treat addiction. But at low doses (typically 1.5-4.5mg), something interesting happens: it briefly blocks opioid receptors, triggering your body to upregulate endorphin production and modulate immune function.

The result is reduced inflammation and a rebalancing of immune responses—which is why LDN has shown promise in conditions ranging from fibromyalgia to Crohn's disease to multiple sclerosis.

LDN Side Effects: What I Tell My Patients

One of the reasons I appreciate LDN is its favorable side effect profile. But "favorable" doesn't mean "none," and I believe in honest medicine—telling patients what to expect, good and bad.

Common side effects (usually temporary):

• Vivid dreams or sleep disturbances – This is the most common complaint, especially in the first few weeks. Taking LDN in the morning instead of at bedtime often resolves this.
• Mild headaches – Usually diminish as the body adjusts.
• Nausea or GI discomfort – Typically mild and temporary.
• Fatigue – Paradoxically, some patients feel tired initially before experiencing the increased energy that often comes with LDN.

What the research shows:

Side effects are reported in less than 8% of patients taking LDN, and they're generally mild. A 2024 retrospective study found that over half of chronic pain patients reported symptom relief, with the most common improvements being reduced pain and fatigue.

My approach to minimizing side effects:

I start patients low and go slow. Many practitioners jump straight to 4.5mg, but I often begin at 0.5-1mg and titrate up over several weeks. For very sensitive patients—those with conditions like MCAS or severe chronic fatigue—I sometimes start even lower, at microgram doses.

This isn't just about tolerability. I've found that some patients actually respond better to lower doses. About one-third of patients don't respond to standard LDN protocols, and for some of them, the issue is that we're pushing too hard, too fast.

When LDN Might Help with Hair Loss

LDN isn't a hair loss treatment per se. But for patients whose hair loss is driven by:

• Autoimmune conditions (like alopecia areata or Hashimoto's)
• Chronic systemic inflammation
• Conditions like MCAS that create widespread immune dysregulation

...LDN can be a valuable part of a comprehensive treatment plan. By calming the underlying immune dysfunction, we create conditions where hair can regrow.

An Integrative Treatment Framework

Here's how I approach hair loss in my practice:

Step 1: Comprehensive Testing

Not just standard labs, but functional testing that looks at optimal ranges, not just "normal" ranges. This includes:

• Complete thyroid panel with antibodies
• Iron studies including ferritin
• Vitamin D, zinc, B12, folate
• Comprehensive metabolic panel
• Sex hormones and their metabolites
• Inflammatory markers
• Sometimes gut testing if indicated

Step 2: Address Root Causes

This might mean:

• Optimizing thyroid function (not just getting TSH into "normal" range)
• Repleting nutrient deficiencies with bioavailable forms
• Balancing hormones through lifestyle, supplements, or bioidentical hormones
• Healing the gut
• Reducing toxic burden

Step 3: Targeted Therapies

Depending on the individual, this might include:

• PRP (Platelet-Rich Plasma) – Uses your body's own growth factors to stimulate follicles
• Low-dose naltrexone – For autoimmune or inflammatory components
• Botanical support – Saw palmetto, rosemary, green tea, and others have evidence for supporting hair health
• Mind-body approaches – Chronic stress and elevated cortisol directly impact hair growth cycles

Step 4: Patience and Realistic Expectations

Hair grows slowly. The hair cycle means it often takes 3-6 months to see the effects of any intervention. I prepare patients for this timeline so they don't give up prematurely.

The Honest Truth

I practice what I call "honest medicine." That means I tell patients:

• Not everyone responds to every treatment
• Some hair loss is genuinely genetic and progressive
• We can often slow progression and sometimes reverse it, but I can't promise miracles
• The goal is optimizing your overall health, with hair regrowth as a welcome benefit

What I can promise is that we'll look deeper than "it's just genetics." We'll investigate what your body is trying to tell you. And we'll address the root causes, not just the symptoms.

Because your hair isn't just about vanity. It's a signal. And signals are worth listening to.

Dr. Yoon Hang Kim is a board-certified preventive medicine physician specializing in integrative and functional medicine. He has been practicing integrative medicine since 1999 and has presented at multiple LDN Research Trust international conferences. He provides telemedicine consultations through Direct Integrative Care, serving patients in Iowa, Illinois, Missouri, Georgia, Florida, and Texas.

Learn more at directintegrativecare.com

Keywords: integrative medicine hair loss, functional medicine hair loss, LDN side effects, low dose naltrexone side effects, hair loss treatment, hair thinning causes, thyroid hair loss, autoimmune hair loss, holistic hair loss treatment, functional medicine approach

Yoon Hang Kim MD MPH

Quick Answer: Does LDN Cause Hair Loss?

• No direct evidence exists that LDN causes hair loss as a primary side effect
• Clinical trials consistently list vivid dreams, sleep changes, and headaches as the most common side effects
• Hair loss in LDN patients typically relates to the underlying autoimmune condition, thyroid imbalance, or nutritional deficiency
• LDN may actually help certain types of autoimmune hair loss, with studies showing disease stabilization in 70-80% of patients with frontal fibrosing alopecia
• Timing matters: Hair loss occurring 2-3 months after a trigger may be Telogen Effluvium, a temporary stress response

The relationship between low-dose naltrexone and hair health is far more complex than a simple cause-and-effect. For most people experiencing hair thinning while on LDN, the real culprit is usually the autoimmune condition, thyroid imbalance, nutritional deficiency, or stress that prompted LDN treatment in the first place.

I’m Dr. Yoon Hang Kim, a board-certified physician specializing in integrative medicine and functional medicine who has prescribed and refined LDN protocols for over two decades across conditions ranging from autoimmune disorders to chronic pain. In my extensive clinical experience with patients concerned about LDN and hair loss, I’ve found that most cases stem from undertreated thyroid issues, iron deficiency, or the autoimmune process itself rather than the medication. Let’s explore what the science really shows and how to approach hair health when taking LDN.

Does LDN Cause Hair Loss? Unpacking the Evidence

The scientific evidence regarding whether LDN causes hair loss is nuanced. While some individuals report hair changes on LDN, this isn’t a commonly recognized side effect in clinical studies.

Standard-dose naltrexone (50mg and above) has occasionally been associated with hair loss, though it’s uncommon. Low-dose naltrexone (0.5-4.5mg) works through an entirely different mechanism, focusing on immune modulation and endorphin upregulation rather than sustained opioid receptor blockade. Published studies investigating LDN across fibromyalgia, multiple sclerosis, and inflammatory bowel disease consistently track adverse events but rarely mention hair loss among significant findings (Younger et al., 2014; Toljan & Vrooman, 2023).

The known side effects of LDN are typically mild and transient: vivid dreams occur in approximately 20-30% of patients, along with occasional sleep disturbances and headaches. These typically resolve within the first few weeks of treatment as the body adjusts.

Potential Indirect Links

While LDN doesn’t directly cause hair loss, indirect connections may exist. Temporary hormonal shifts or endocrine adjustments during the initial weeks of LDN therapy could, in sensitive individuals, contribute to hair shedding. More commonly, patients experiencing hair loss concerns while on LDN may have Telogen Effluvium—a stress-induced shedding pattern that appears 2-3 months after a physiological trigger. The trigger may have been the illness that led them to seek LDN treatment in the first place.

Anecdotal Reports vs. Clinical Data

Patient forums contain stories linking LDN to hair loss, but controlled trials tell a different story. Multiple studies across fibromyalgia, multiple sclerosis, and Crohn’s disease carefully track adverse events yet consistently omit hair loss from significant findings. This discrepancy suggests anecdotal reports likely reflect underlying conditions rather than LDN effects.

The Real Culprits: When It’s Not the LDN

In my practice at www.directintegrativecare.com, serving patients across Iowa, Illinois, Missouri, Florida, Georgia, and Texas, I find that hair loss often signals deeper imbalances rather than medication effects. The conditions that bring patients to LDN in the first place frequently cause hair loss themselves.

Iron Deficiency: A Hidden Cause of Hair Loss

When patients come to me worried that LDN is causing their hair loss, one of the first things I investigate is their iron status. Iron deficiency is remarkably common—especially in women of childbearing age—and frequently flies under the radar because most practitioners only check hemoglobin. You can have perfectly normal hemoglobin and still be profoundly iron deficient.

The Ferritin-Hair Connection

Iron is essential for DNA synthesis in rapidly dividing cells, and hair follicle matrix cells are among the fastest-dividing cells in the human body. When iron stores drop, your body prioritizes vital organs, and hair follicles lose the competition. Research from China examining 193 patients with telogen effluvium found that serum ferritin levels were significantly lower in hair loss patients compared to healthy controls, with an optimal diagnostic cutoff around 24.5 ng/mL (Cheng et al., 2021).

Here’s what I’ve learned from two decades of clinical practice: the laboratory “normal” range for ferritin is not the same as the “optimal” range for hair health. Most labs report ferritin as normal anywhere from 12-150 ng/mL in women. But in functional medicine, we’ve found that hair follicles often need ferritin levels above 70 ng/mL to function optimally (Rushton, 2002).

Who’s at Risk?

A systematic review and meta-analysis examining iron deficiency in women with nonscarring alopecia found that approximately 21% of women with hair loss had ferritin deficiency, and the prevalence increased substantially when using a higher threshold of 30-40 ng/mL (Gafter-Gvili & Cohen, 2022). Risk factors for iron deficiency that I commonly see in my practice include heavy menstrual periods, vegetarian or vegan diets without adequate supplementation, gastrointestinal conditions affecting absorption (particularly relevant for my MCAS patients), chronic inflammation, and recent blood donation.

The Functional Medicine Approach to Iron Assessment

When evaluating a patient with hair loss, I order a comprehensive iron panel rather than just ferritin alone. This includes serum iron, total iron-binding capacity (TIBC), transferrin saturation, and ferritin. Ferritin can be falsely elevated in inflammatory conditions—particularly relevant for patients with autoimmune conditions or chronic infections—so the complete picture matters.

For my patients with low ferritin and hair loss, I typically recommend iron supplementation with vitamin C to enhance absorption, alongside addressing any underlying causes of deficiency. Patience is essential: hair growth cycles are long, and it typically takes 3-6 months of optimized iron stores before visible improvement occurs.

The Flip Side: Can LDN Actually Treat Hair Loss?

While some people worry about LDN causing hair loss, a growing body of evidence suggests it may actually be an effective treatment for certain types of hair loss, particularly those with an autoimmune component. By modulating the immune system and reducing inflammation, LDN can help calm the overactive immune response that targets and damages hair follicles.

Evidence for LDN in Autoimmune Alopecia

LDN’s ability to increase endorphin production and regulate T-regulatory cells can be particularly beneficial for autoimmune-driven hair loss. The most compelling evidence comes from studies on frontal fibrosing alopecia (FFA) and lichen planopilaris (LPP), both scarring forms of alopecia.

A retrospective study from the University of Pittsburgh examining 52 patients with FFA and LPP who had failed multiple prior treatments found remarkable results with LDN. For patients with FFA, 75% achieved disease stability within 6.4 months, with significant improvements in pruritus and perifollicular erythema. For LPP patients, 65% achieved disease stability within 7.3 months (Shaker et al., 2024).

A prospective open-label study from Washington University enrolled 43 patients with FFA and LPP and followed them for 12 months on 3mg daily LDN. The frontal hairline remained stable in FFA patients throughout the study period, with significant improvements in itching, burning, and erythema scores (Hamel et al., 2023).

Conditions Where LDN Shows Promise

Alopecia Areata: This autoimmune condition where the body attacks its own hair follicles, causing patchy hair loss, may benefit from LDN’s immune-modulating effects. While formal trials are limited, the mechanism of action aligns well with the disease pathophysiology (Mesinkovska, 2018).

Lichen Planopilaris and Frontal Fibrosing Alopecia: These scarring alopecias characterized by inflammation show the most robust evidence for LDN benefit. Multiple studies demonstrate that LDN can halt progression and, in some cases, promote regrowth in follicles not yet permanently damaged.

Trichodynia (Scalp Pain/Discomfort): Even in patients where LDN doesn’t produce measurable hair regrowth, many report significant improvement in scalp discomfort, itching, and burning (Wismuth et al., 2019).

Dosage and Timelines for Hair Restoration

When used for hair loss, LDN is typically prescribed in the same low-dose range as for other autoimmune conditions. Based on my clinical experience and the published literature, I usually start patients at 1.5mg and gradually increase to a target dose of 4.5mg per day. The University of Pittsburgh study used 4.5mg daily in most patients, while the Washington University study used 3mg daily—both with positive outcomes.

Patience is essential. Hair growth cycles are long, typically 2-7 years for scalp hair. While some patients notice a reduction in shedding and scalp inflammation within 4-6 weeks, visible regrowth usually takes 3-6 months or longer. Optimal results are often seen after at least 6-12 months of consistent use.

Practical Summary: LDN and Hair Health

Conclusion - Does LDN Cause Hair Loss? Integrative Medicine & Functional Medicine Perspective

The question “Does LDN cause hair loss?” has a nuanced answer. Based on published research and my two decades of clinical experience, LDN does not appear to directly cause hair loss. Rather, patients experiencing hair changes while on LDN typically have underlying conditions—autoimmune disease, thyroid dysfunction, iron deficiency, or nutritional imbalances—that are the true culprits.

In fact, for patients with autoimmune-related hair loss like frontal fibrosing alopecia, lichen planopilaris, and potentially alopecia areata, LDN may be part of the solution rather than the problem. The key is individualized assessment, addressing all contributing factors, and working with a practitioner experienced in both LDN and the complex interplay of autoimmunity, hormones, and nutritional status.

For patients struggling with hair loss alongside chronic complex conditions, working with a physician experienced in LDN, integrative medicine, and functional medicine can make the difference between frustration and meaningful improvement.

About the Author

Yoon Hang Kim, MD is a board-certified preventive medicine physician specializing in integrative and functional medicine. A graduate of the University of Arizona Integrative Medicine Fellowship, Dr. Kim has been prescribing LDN for over two decades and has presented at multiple LDN Research Trust conferences internationally. He is the author of two books on LDN therapy and practices telemedicine through www.directintegrativecare.com, serving patients in Iowa, Illinois, Missouri, Georgia, Florida, and Texas.

Website: www.directintegrativecare.com

References

Cheng, T., Fang, H., Wang, Y., Wang, Y., Yang, Z., Wu, R., & Yang, D. (2021). The diagnostic value of serum ferritin for telogen effluvium: A cross-sectional comparative study. Clinical, Cosmetic and Investigational Dermatology, 14, 137-141. https://doi.org/10.2147/CCID.S291170

Gafter-Gvili, A., & Cohen, A. (2022). Iron deficiency and nonscarring alopecia in women: Systematic review and meta-analysis. Skin Appendage Disorders, 8(2), 83-92. https://doi.org/10.1159/000519952

Hamel, R. K., Chen, L., O’Connell, C., & Mann, C. (2023). Oral low-dose naltrexone in the treatment of frontal fibrosing alopecia and lichen planopilaris: An uncontrolled open-label prospective study. Cureus, 15(1), e34169. https://doi.org/10.7759/cureus.34169

Mesinkovska, N. A. (2018). Emerging unconventional therapies for alopecia areata. Journal of Investigative Dermatology Symposium Proceedings, 19(1), S32-S33. https://doi.org/10.1016/j.jisp.2017.10.002

Olsen, E. A., Reed, K. B., Cacchio, P. B., & Caudill, L. (2010). Iron deficiency in female pattern hair loss, chronic telogen effluvium, and control groups. Journal of the American Academy of Dermatology, 63(6), 991-999. https://doi.org/10.1016/j.jaad.2009.12.006

Rushton, D. H. (2002). Nutritional factors and hair loss. Clinical and Experimental Dermatology, 27(5), 396-404. https://doi.org/10.1046/j.1365-2230.2002.01076.x

Shaker, N., Petrin, C., Miller, D., & Gathers, R. (2024). Attenuation of disease process following treatment with low-dose naltrexone in patients with frontal fibrosing alopecia and lichen planopilaris: A retrospective study. Journal of the American Academy of Dermatology, 91(2), 421-423. https://doi.org/10.1016/j.jaad.2024.03.028

Toljan, K., & Vrooman, B. (2023). Efficacy of low-dose naltrexone and predictors of treatment success or discontinuation in fibromyalgia and other chronic pain conditions. Biomedicines, 11(4), 1087. https://doi.org/10.3390/biomedicines11041087

Wismuth, A., Bertolini, M., & Mesinkovska, N. A. (2019). Low-dose naltrexone: A novel adjunctive treatment in symptomatic alopecias? Journal of the American Academy of Dermatology, 81(4), AB104. https://doi.org/10.1016/j.jaad.2019.06.425

Younger, J., Parkitny, L., & McLain, D. (2014). The use of low-dose naltrexone (LDN) as a novel anti-inflammatory treatment for chronic pain. Clinical Rheumatology, 33(4), 451-459. https://doi.org/10.1007/s10067-014-2517-2

Disclaimer: This publication is for educational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider before starting or modifying any treatment regimen.

© 2025 Yoon Hang Kim, MD | www.directintegrativecare.com