Fact vs. Fiction: Does Ivermectin Cause Hair Loss?

October 7, 2025 •

4 min read

While ivermectin is a broad-spectrum antiparasitic agent, a pressing question has emerged in public discourse: Does ivermectin cause hair loss? [1.5.3] The available clinical data suggests the answer is more complex than a simple yes or no, pointing towards other contributing factors.

Quick Summary

An in-depth analysis of the scientific evidence regarding ivermectin and hair loss. This content clarifies the drug's known side effects versus confounding factors like post-illness hair shedding (telogen effluvium).

Key Points

Not a Direct Side Effect: Hair loss (alopecia) is not listed as a common or recognized side effect in official ivermectin prescribing information [1.8.3].
Telogen Effluvium is Key: Hair shedding reported after taking ivermectin is often linked to telogen effluvium, a condition caused by significant physical stress like a major illness [1.3.1, 1.3.3].
Underlying Illness is the Likely Cause: The illness for which ivermectin was taken (e.g., COVID-19) is a more probable cause of subsequent hair loss than the drug itself [1.6.4].
Known Side Effects: The documented side effects of ivermectin include dizziness, nausea, skin rash, and in severe cases, neurological problems—not hair loss [1.8.5].
Consult a Professional: Anyone experiencing significant hair loss should consult a doctor to determine the true underlying cause, which could include stress, hormonal changes, or nutritional deficiencies [1.3.5].
Misinformation Context: The association gained traction during the COVID-19 pandemic, where the virus itself is a known and strong trigger for telogen effluvium [1.6.2].

Understanding Ivermectin: What It Is and How It Works

Ivermectin is an FDA-approved medication primarily used to treat parasitic infections [1.5.2]. Its approved uses in humans include tablets (brand name Stromectol) for intestinal strongyloidiasis (threadworm) and onchocerciasis (river blindness) [1.5.1, 1.5.6]. Topical forms are also approved for treating head lice (Sklice) and rosacea (Soolantra) [1.5.2]. The medication works by binding to channels in the nerve and muscle cells of invertebrates, leading to hyperpolarization, paralysis, and death of the parasite [1.5.5]. This mechanism has low affinity for corresponding channels in mammals, and ivermectin does not readily cross the human blood-brain barrier, which contributes to its safety profile when used as prescribed [1.5.5].

During the COVID-19 pandemic, ivermectin gained significant attention, but the FDA has not authorized or approved it for the prevention or treatment of COVID-19, citing a lack of data on its safety and effectiveness for this purpose [1.5.6].

The Core Question: Does Ivermectin Cause Hair Loss?

Based on official prescribing information and data from major health organizations, hair loss (alopecia) is not listed as a common or direct side effect of ivermectin [1.8.1, 1.8.2, 1.8.3]. Extensive lists of side effects from sources like the Mayo Clinic and MedlinePlus detail reactions ranging from dizziness and nausea to severe skin reactions, but do not include hair loss [1.8.1, 1.8.2]. While one study using a zebrafish model noted ivermectin was toxic to sensory hair cells (related to hearing and balance), this is distinct from the follicles that produce hair on the scalp [1.2.1, 1.7.2]. The overwhelming majority of clinical data and official drug information does not establish a causal link between prescribed ivermectin use and hair shedding.

Indirect Links: Telogen Effluvium and Confounding Factors

The confusion likely stems from a condition called telogen effluvium, a temporary form of hair shedding that occurs a few months after a significant physical or emotional stressor [1.3.1, 1.3.4]. The hair growth cycle has three main phases: anagen (growth), catagen (transition), and telogen (resting/shedding) [1.3.2]. A major stress can shock the body, causing a large number of hairs to prematurely shift from the growth phase to the shedding phase [1.3.3].

Common triggers for telogen effluvium include:

Severe Illness or High Fever: Infections like COVID-19, the flu, or pneumonia are well-documented triggers [1.3.4, 1.6.5].
Major Surgery or Physical Trauma [1.3.3].
Significant Psychological Stress [1.3.2].
Hormonal Changes (e.g., childbirth, thyroid disorders) [1.3.5].
Certain Medications: This includes retinoids, beta-blockers, and anticoagulants [1.4.5].

Many anecdotal reports of hair loss linked to ivermectin surfaced during the COVID-19 pandemic. However, COVID-19 infection itself is a strong trigger for telogen effluvium, with studies showing hair loss occurring two to three months after the illness [1.6.2, 1.6.3, 1.6.5]. The physiological stress, fever, and inflammation associated with the viral infection are the more probable causes of the hair shedding experienced by these individuals, rather than the ivermectin they may have taken [1.6.1, 1.6.4].

Officially Documented Side Effects of Ivermectin

While hair loss is not a recognized side effect, ivermectin does have a range of potential adverse effects, especially if misused or taken in large doses. According to the FDA and other medical sources, these include:

Common Side Effects:

Dizziness [1.8.5]
Nausea and diarrhea [1.8.5]
Itchy skin (pruritus) [1.8.3]
Headache and muscle aches [1.8.5]

Serious Side Effects:

Severe skin rash [1.8.5]
Neurological effects like confusion, balance problems, or seizures [1.8.5]
Hypotension (low blood pressure) [1.8.6]
Liver injury (rare) [1.2.6]
Mazzotti reaction in patients treated for onchocerciasis, which includes fever, rash, and joint pain [1.8.1].

The FDA warns that taking large doses or using veterinary formulations can be dangerous and lead to overdose, resulting in symptoms like seizures, coma, and even death [1.5.6, 1.8.6].

Drug Side Effect Comparison Table

To put this in perspective, here is a comparison of ivermectin with a medication known to cause hair loss.


Feature	Ivermectin	Docetaxel (Chemotherapy)	Doxycycline (Antibiotic)
Primary Use	Antiparasitic infections (e.g., river blindness, threadworm) [1.5.1]	Cancer treatment (e.g., breast, lung, prostate) [1.4.1]	Bacterial infections, acne, malaria prevention
Common Side Effects	Dizziness, nausea, diarrhea, rash [1.8.5]	Nausea, fatigue, mouth sores, fluid retention, nerve pain [1.4.1]	Photosensitivity, nausea, diarrhea
Association with Hair Loss	Not a recognized direct side effect [1.8.3]	Very common and often severe (anagen effluvium); can be permanent [1.4.1]	Rare; can occasionally trigger telogen effluvium [1.4.3]

Conclusion

There is no significant scientific evidence from clinical trials or official drug information to suggest that ivermectin directly causes hair loss. The association that has appeared in public discussion is largely anecdotal and better explained by telogen effluvium, a temporary hair shedding condition triggered by the underlying illnesses (like COVID-19) for which the drug was sometimes used off-label [1.6.4]. The physiological and emotional stress of a severe infection is a well-established cause of this type of hair loss, which typically resolves on its own within several months [1.6.2]. Anyone experiencing significant hair loss should consult a healthcare professional to identify the true underlying cause rather than attributing it to a medication not known to have this side effect.

For more information on approved medications, you can visit the FDA's drug database.

Frequently Asked Questions

No, hair loss (alopecia) is not listed as a common side effect in the official prescribing information for ivermectin provided by regulatory bodies like the FDA or in databases like the Mayo Clinic [1.2.2, 1.8.3].

The most likely cause is a condition called telogen effluvium, which is temporary hair shedding triggered by the physical stress of the COVID-19 infection itself. High fever and illness are well-known triggers for this condition [1.6.1, 1.6.4].

Telogen effluvium is a form of temporary hair loss that occurs after a stressful event, illness, or hormonal change. It happens when a large number of hairs are pushed into the 'shedding' (telogen) phase of the growth cycle at once [1.3.3, 1.3.4].

Hair shedding from telogen effluvium usually begins 2 to 3 months after the triggering event (like an illness) and typically resolves on its own within 3 to 6 months as the hair returns to its normal growth cycle [1.6.1, 1.6.5].

In humans, ivermectin tablets are FDA-approved to treat parasitic worm infections like strongyloidiasis and onchocerciasis. Topical formulations are approved for head lice and skin conditions like rosacea [1.5.2, 1.5.6].

Yes, many medications can cause hair loss. The most well-known are chemotherapy drugs (anagen effluvium), but others like retinoids, beta-blockers, anticoagulants, and some antidepressants can also trigger temporary hair shedding (telogen effluvium) [1.4.2, 1.4.3, 1.4.5].

Common side effects of oral ivermectin include dizziness, nausea, diarrhea, stomach pain, and skin rash [1.8.3, 1.8.5]. It's crucial to only take medication as prescribed by a healthcare professional.