Researchers explained that when minoxidil is applied to the scalp, it doesn't just work locally – it gets absorbed into the bloodstream.
Published Jan 04, 2026 | 7:00 AM ⚊ Updated Jan 04, 2026 | 7:00 AM
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Synopsis: A global safety study warns that over-the-counter minoxidil – popular hair loss treatment – is causing excessive hair growth in infants through skin contact and breastfeeding, and triggering serious eye disorders in adults. Researchers urge stricter regulation, clearer warnings, and better counselling, highlighting risks from unmonitored use, especially in vulnerable populations like children and pregnant or breastfeeding women.
A widely used over-the-counter hair loss treatment is causing excessive hair growth in infants through skin contact and breastfeeding, whilst triggering serious eye disorders in adults as the drug circulates through the bloodstream, according to a global safety study that has raised concerns about its unregulated use.
Minoxidil, originally developed as a blood pressure medication, was later reformulated as a topical treatment for hair loss after doctors noticed it promoted hair growth as a side effect. The drug is now widely available without prescription in the form of sprays and foams for treating androgenetic alopecia, commonly known as male or female pattern baldness.
The study, published in Archives of Dermatological Research, analysed adverse drug reaction reports submitted to the World Health Organization’s global safety database, VigiBase, up to March 2025.
Researchers from the Indian Pharmacopoeia Commission under the Ministry of Health and Family Welfare, working with the All India Institute of Medical Sciences, reviewed both global data and India-specific reports to assess risks associated with the popular hair loss treatment.
Out of 2,664 global reports of minoxidil-suspected infantile hypertrichosis – a condition involving excessive and abnormal hair growth, sometimes described as fur-like – 45 cases involved children aged under two years. The analysis showed that 22.2 percent of these cases resulted from maternal exposure during pregnancy or breastfeeding, whilst 44.4 percent followed accidental exposure and 33.3 percent had an unknown source.
No cases were reported from India, though researchers cautioned that under-reporting remains a possibility given the drug’s widespread availability in the country.
The condition has been linked to infants’ thin skin and higher absorption capacity, which makes them particularly vulnerable when exposed to the drug.
“There is potential for a much larger number of cases which haven’t been identified, owing to low reporting in the region,” the authors noted, adding that the numbers are “concerning, particularly considering the over-the-counter availability and widespread use of minoxidil.”
The researchers explained that infants can be exposed through multiple routes. “The drug was inadvertently absorbed via skin-to-skin contact or accidentally ingested by the infants through breastmilk or other unknown sources,” the study noted.
When parents apply minoxidil to their scalp, the drug can transfer to infants through direct contact during holding, cuddling, or feeding. The researchers explained that “infants who come into contact with the drug can develop an exaggerated response, owing to their thin skin and high absorption capacities.”
The study also highlighted that minoxidil’s hair growth mechanism “involves vasodilation, increasing blood flow to hair follicles and its action on potassium channels of the hair follicles.” This same mechanism, when activated in infants’ bodies, leads to excessive hair growth across their entire body rather than just the scalp.
Despite minoxidil being contraindicated – meaning it should not be used – in pregnant and breastfeeding women, its easy availability and lack of awareness about potential harm may be contributing to widespread use among such populations.
The study also identified 1,669 global cases of eye disorders associated with minoxidil use, including 25 cases reported from India. Common symptoms included eyelid swelling, eye irritation, blurred vision, and central serous chorioretinopathy – a condition where fluid accumulates under the retina, the light-sensitive tissue at the back of the eye.
Of the Indian reports, nine were classified as serious, with four confirmed after removing duplicate records. These included three cases of central serous chorioretinopathy and one case of retinal artery occlusion, where blood flow to the retina becomes blocked.
The researchers explained that when minoxidil is applied to the scalp, it doesn’t just work locally – it gets absorbed into the bloodstream. “The vasodilatory mechanism of minoxidil resulting in increased vascular permeability in the choroid and subsequent fluid leakage into the subretinal space, is thought to be related to the ocular issues such as central serous chorioretinopathy and retinal artery occlusion,” the study stated.
In simpler terms, minoxidil widens blood vessels throughout the body, including those in the choroid – the layer of blood vessels behind the retina. This makes these vessels “leakier,” allowing fluid to seep out and accumulate under the retina, causing vision problems.
“While Minoxidil has proven efficacy in managing androgenetic alopecia in adults, its widespread and often unregulated availability raises significant safety concerns, particularly in vulnerable populations such as infants and young children,” the authors said.
The researchers called for clearer warnings on product labels, stronger regulation of over-the-counter sales, and improved counselling by healthcare professionals. They stressed the need to include serious ocular adverse events more prominently in patient information leaflets and urged regulators to address misleading marketing claims that promote unsupervised use.
“There is a pressing need for enhanced patient counselling and caregiver education regarding the potential risks of minoxidil, especially when used in households with children,” the authors said.
“Regulatory action should be taken and such serious adverse reaction should be mentioned in the patient information leaflet to be known by medical practitioners prescribing the drug.”
The study emphasised that misleading marketing claims and the ease of over-the-counter access contribute to misuse and accidental exposure, which could otherwise be avoided through proper guidance and oversight.
“Given that these eye disorders are highlighted in patient information leaflets as a rare event, it would be prudent for healthcare professionals to consider minoxidil as a potential cause when patients present with ocular symptoms,” the authors added.
The findings aim to strengthen drug safety awareness and improve reporting practices, particularly in countries like India where minoxidil use remains widespread and largely unmonitored.
(Edited by Amit Vasudev)
