Oral Minoxidil (or Minoxidil Capsules) is a prescription medication that can be used off label as an alternative to Minoxidil Spray for treating male pattern baldness.
While Minoxidil 5% Spray is the licensed formulation for hair loss, oral minoxidil has become increasingly popular due to its convenience and growing body of evidence supporting its effectiveness.
However, because oral minoxidil is taken systemically rather than applied directly to the scalp, it's understandable that many people have questions about its safety. In this blog, we'll explore what the research says about oral minoxidil, the potential side effects to be aware of, and whether it can be a safe option for treating hair loss.
How does minoxidil work for hair loss?
Minoxidil works by widening blood vessels, allowing more blood to reach the scalp. This increased blood flow delivers oxygen and nutrients to the hair follicles, helping to support healthy hair growth.
It may also help counteract some of the effects of male pattern baldness by influencing the hair growth cycle. Research suggests that minoxidil can shorten the telogen (shedding) phase and prolong the anagen (growth) phase, meaning hairs spend more time actively growing and less time resting before they fall out.
In addition, minoxidil is thought to stimulate growth-promoting pathways within the follicle. This includes increasing levels of vascular endothelial growth factor (VEGF), which supports blood vessel formation around the follicle, and activating the beta-catenin pathway, which plays an important role in hair growth and regeneration.
What’s the difference between oral and topical minoxidil?
The main differences are administration, licensing, and side effects.
Administration
Oral Minoxidil is usually prescribed as one daily capsule, taken with or without food. Minoxidil 5% Spray is a liquid solution applied directly to the scalp twice-a-day.
Licensing
Minoxidil Spray is a licensed treatment for male pattern baldness, in both men and women. Oral Minoxidil is considered ‘off label’, meaning it can be prescribed by a pharmacist or GP to treat hair loss, taking a patient’s medical history and risk factors into consideration.
Side effects
The most common side effects associated with Minoxidil Spray are localised – things like skin irritation, itchiness and dryness where the solution is applied. Systemic side effects with Minoxidil Spray are very rare, as very little minoxidil is absorbed into the bloodstream. Oral Minoxidil comes with a higher risk of systemic side effects, as it is absorbed directly into the bloodstream.
What are the potential side effects with Oral Minoxidil?
The most common side effect is hypertrichosis, meaning it can cause more hair growth on parts of the body you didn’t intend (like body hair). Cardiovascular side effects are rarer, but occasionally experienced by some users.
In the largest study to date investigating the safety of oral minoxidil for hair loss, researchers analysed data from 1,404 patients. The most commonly reported side effect was hypertrichosis, which affected 15.1% of participants. However, only 14 patients chose to stop treatment because of it.
Other side effects were relatively uncommon and included lightheadedness (1.7%), fluid retention (1.3%), tachycardia (0.9%), headache (0.4%), swelling around the eyes (0.3%), and insomnia (0.2%). Overall, just 1.2% of patients discontinued treatment due to side effects, and no serious adverse events were reported.
Another potential side effect which users of either Oral Minoxidil and Minoxidil Spray might encounter is a temporary shedding phase in the early days of treatment. Even though it can feel alarming to go through a period of increased shedding, it’s actually a sign the treatment is working. Minoxidil works by shortening the telogen phase and pushing follicles back into the active growth phase, anagen. So
Minoxidil is essentially speeding up the hair growth cycle, pushing dormant follicles back into the growth phase – but for this to happen, the old hair needs to be shed to make way for new, healthier hairs. As the hair cycle normalises, shedding typically settles and regrowth can begin to become more noticeable.
In a trial of 90 men using either 5mg of Oral Minoxidil or 5% Minoxidil Spray, 9% using oral minoxidil and 7% using the spray experienced this early shedding phase during the first 2 months of treatment.
Is Oral Minoxidil safe to use long-term?
Side effects from oral minoxidil are usually reversible and typically improve after treatment is stopped. To date, there have been no reports of permanent side effects caused by oral minoxidil. In some cases, side effects may even settle on their own as the body adjusts to treatment, or after the dose has been reduced.
There are also simple ways to manage some of the more common side effects. For example, people who experience light-headedness may find it helpful to take their tablet before bed, stand up slowly from sitting or lying positions, stay well hydrated, and, if applicable, speak to their doctor about adjusting any blood pressure medication they are taking. Mild fluid retention may be improved by reducing salt intake.
If side effects persist or become bothersome, it's important to speak with your GP or prescriber. They may recommend lowering the dose or stopping treatment altogether.
Current evidence has not identified any specific side effects associated with using Oral Minoxidil for a long time. In fact, some studies suggest that patients are more likely to stick to treatment with Oral Minoxidil than Minoxidil Spray, largely because taking a daily tablet is often more convenient than applying a product to the scalp every day.
All of our blog articles are reviewed by our Medical Director before publication.
