Based on PubMed | Can losartan cause hair loss, and how common is this side effect?

Overview

Losartan (brand name Cozaar) can be associated with hair loss (alopecia), but this appears to be an uncommon side effect. The official prescribing information lists alopecia among skin-related adverse reactions reported with losartan. ^[1] Alopecia is again included in consumer and professional drug information summaries for Cozaar. ^{[2] [3]} However, large clinical trials and safety reviews generally describe losartan as well‑tolerated, and they do not highlight hair loss as a common or prominent adverse event, suggesting it is rare. ^{[4] [5]}

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What official drug labels say

• The Cozaar (losartan) label lists “alopecia” in the Skin adverse reactions section, alongside dermatitis, dry skin, rash, urticaria, and photosensitivity. ^[1] This indicates that hair loss has been observed, typically in postmarketing and/or clinical trial adverse event reports. ^[1]
• Consumer and professional DailyMed entries for Cozaar similarly include alopecia within reported skin reactions. ^{[2] [3]}

These listings confirm a possible link but do not provide a precise frequency for hair loss. ^{[1] [2]}

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How common is hair loss with losartan?

• In controlled trials, losartan’s overall adverse event profile was similar to placebo, and the most common event with higher-than-placebo incidence was dizziness (~2.4% vs 1.3%). Hair loss was not reported as a common event in these trial summaries, implying alopecia is uncommon or rare. ^[4]
• Early and larger clinical experience reports likewise emphasize a low incidence of adverse events overall, without singling out alopecia as frequent. ^[5]

Because official materials acknowledge alopecia without giving a rate, and trials do not show it as common, the side effect likely occurs infrequently. ^{[1] [4]}

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Possible mechanisms of drug‑induced hair loss

• Drug‑induced hair loss most often presents as telogen effluvium (diffuse shedding), and is usually reversible after stopping the offending medication. ^[6]
• The mechanism for ARBs like losartan causing alopecia is not well defined; when drug‑related, it may reflect a nonspecific impact on the hair cycle rather than direct follicle toxicity. ^[6]

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Distinguishing causes of hair loss

Many factors can contribute to shedding, and it may not always be due to losartan:

• Stress, illness, thyroid issues, iron deficiency, and other medications can also cause telogen effluvium. ^[6]
• Some antihypertensive classes (notably certain beta‑blockers) have more consistent associations with hair loss than ARBs; losartan’s association appears more sporadic. ^[7]

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What to do if you notice hair loss

• Discuss timing: If shedding began after starting or changing losartan, a drug link may be possible. A clinician can assess for other causes (labs for thyroid, iron, etc.). ^[6]
• Consider reversibility: Drug‑induced telogen effluvium often improves within months after withdrawal of the trigger; do not stop losartan without medical guidance because it controls blood pressure and protects organs. ^[6]
• Manage shedding: Gentle hair care, minimizing heat/chemical treatments, and addressing nutritional gaps may help while the underlying cause is evaluated. ^[6]

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Safety context of losartan

• Overall, losartan is widely used and well tolerated in large trials, with adverse event rates comparable to placebo. ^[4]
• Postmarketing reports for losartan include various reactions but typically without quantified frequencies; alopecia is listed among skin reactions, underscoring that it has been observed but is not necessarily common. ^[1]

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Summary Table: Hair loss and losartan

Topic	Evidence/Notes
Is hair loss reported with losartan?	Yes; alopecia appears in the official label under skin adverse reactions. [1] [2]
Frequency in trials	Not specified; large trials describe losartan as well‑tolerated and do not report alopecia as common. [4] [5]
Likely pattern	Often resembles telogen effluvium (diffuse shedding), typically reversible. [6]
Clinical approach	Evaluate timing, rule out other causes, avoid stopping losartan abruptly; consider alternatives if a drug link is likely. [6]

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Bottom line

Losartan can be associated with hair loss according to official labeling, but the side effect appears to be uncommon, and large clinical studies do not identify it as a frequent issue. ^{[1] [4]} If you experience noticeable shedding after starting losartan, it may be worth discussing with your clinician to look for other causes and to consider options if a medication effect is suspected. ^[6]