Complete Guide to Minoxidil for Hair Loss

Minoxidil is one of the most popular and well-studied hair loss treatments available. It started life as a blood pressure tablet. However, its most famous side effect, hair growth, turned it into a first-line treatment for androgenetic alopecia. This is pattern hair loss in both men and women. It is also increasingly being used to help with patchy beard growth. Minoxidil comes in topical form (a serum, foam or spray applied to the scalp or face) and as an oral tablet. This guide explains how minoxidil treats hair loss and why it does not work for everyone. We also explore the difference between oral vs topical minoxidil, best way to use it, side effects and how to get it in the UK.

What is Minoxidil?

Minoxidil was originally developed in the late 1970s as an oral medicine for high blood pressure. Doctors noticed that patients taking it grew thicker hair. By 1988 a topical minoxidil formulation got FDA approval for hair loss. It remains one of only a small number of hair loss treatments with solid evidence behind it. It is also the only topical treatment with formal approval for androgenetic alopecia in both men and women.

The main way minoxidil works is by widening the blood vessels in the scalp and increasing blood flow to the hair follicles. This delivers more oxygen and nutrients to the follicle, and it is thought to prolong the anagen (growth) phase of the hair cycle so that more hairs grow for longer. Although the exact mechanisms by which it works are still not fully understood, the effect is well established. With consistent use, minoxidil can reduce shedding and stimulate regrowth.

Despite its great potential, minoxidil doesn’t work for everyone. The reason for this is that minoxidil is a pro-drug so it is not in its active form when you apply it. The skin has to convert it into its active form, minoxidil sulfate, using an enzyme called sulfotransferase (SULT1A1) which is highly active in some people and less so in others. This conversion step and difference in SULT1A1 activity is the reason topical minoxidil works brilliantly for some people and barely at all for others. We will discuss this in more detail and options for poor responders below.

What Does Minoxidil Treat?

Broadly speaking, minoxidil is useful wherever the goal is to stimulate hair growth and prolong the growth phase of the follicle. As such it’s main uses are:

• Male and female pattern hair loss: This is the main use. Topical minoxidil is a first-line treatment for androgenetic alopecia in both men and women. It helps slow shedding and regrow hair on the scalp particularly at the crown.
• Other types of hair loss: It is also has off-label uses for some other forms of hair thinning, including telogen effluvium. It may also be useful as a supportive treatment in conditions like alopecia areata and CCCA usually under specialist guidance.
• Beard growth: Minoxidil is also an off-label treatment for stimulating patchy or slow beard growth. It works on facial hair the same way it does on the scalp, and is one of the few treatments with some scientific evidence behind it for beards.

At City Skin Clinic, minoxidil is the active we use most often in our hair loss and beard growth treatments. We use it topically in custom compounded serums, alongside other actives where appropriate, designed around each person’s needs.

Minoxidil Strengths & Formulations

Topical minoxidil at 2% and 5% is the only form with formal approval for hair loss in the UK and is available as a serum, foam or spray. Higher strengths, compounded formulas and oral minoxidil are all used off-label or unlicensed and available by prescription-only. Minoxidil comes in three main forms. These differ in strength, how you take them and whether they need a prescription:

• Licensed topical (over the counter): Minoxidil 2% (marketed for women) and 5% (marketed for men), in products such as Regaine. This is the only minoxidil available without a prescription and licenesed for hair loss. Minoxidil 5% is the best studied strength and generally most effective for both men and women.
• Compounded topical (prescription): This is a topical treatment that a compounding pharmacy individually makes according to a doctor’s prescription. Compounding allows different bases and higher strengths (often up to 10%, though 5% to 7% is most common). It also allows combination of minoxidil with other actives like tretinoin or melatonin in a single formula which off-the-shelf products cannot do. As such these formulas allow tailoring of the strength, base and actives to each individual.
• Oral (prescription): Low-dose minoxidil tablets (0.25-5mg) are sometimes used off-label mainly for people who do not respond to topical treatment. As this is a systemic treatment, oral minoxidil needs monitoring for cardiovascular effects.

What Other Treatments Work Best with Minoxidil

Minoxidil stimulates hair growth but does not tackle the hormonal driver behind most pattern hair loss. This is why it is often compounded with other actives in a single serum or used alongside oral DHT blockers. The right combination depends on the person’s health, severity of hair loss and whether the target is the scalp or the beard. The actives most often combined with minoxidil are:

• Tretinoin: This topical retinoid boosts absorption of minoxidil into the scalp and prolongs its activity at the hair follicle so you can use it once a day instead of twice daily. The most common way to use tretinoin for hair loss is in compounded topical minoxidil formulas. This pairing is suitable for scalp hair and beard growth treatments alike.
• Finasteride or dutasteride: These DHT blockers tackle the hormonal driver of androgenetic hair loss. They are available orally or in compound formulas alongside tretinoin in scalp formulas. Finasteride and dutasteride are mainly usually only suitable for hair loss in men and some postmenopausal women.
• Spironolactone: This is an anti-androgen that also addresses the hormonal driver alongside minoxidil’s growth stimulation. It is available in oral and topical form. Oral spironolactone is only suitable for treating pre and postmenopausal women. Topical is available for both men and women.
• Caffeine & melatonin: These supportive actives can stimulate the follicle, regulate the growth cycle and protect against oxidative stress. They are usually compounded with tretinoin in topical hair and beard treatments.
• Hydrocortisone: This is a mild steroid that is sometimes useful in topical hair and beard formulas to reduce irritation from tretinoin and higher strength minoxidil. It is not something you can use indefinitely and often for only up to 3 months continuously.

In addition to the above, microneedling can also help for both scalp and beard hair growth. It can potentially boost absorption of topical hair growth products as well as stimulates the follicles directly.

Why Doesn’t Minoxidil Work for Everyone?

Because topical minoxidil is a pro-drug, it is inactive when you apply it. The scalp has to convert it into its active form, minoxidil sulfate, using an enzyme called sulfotransferase (SULT1A1). However, the amount or activity of that enzyme in the hair follicle is largely genetic. People with high activity respond well. Those with low activity convert very little of the minoxidil they apply and so see little benefit even with diligent use. This is why only around 40% of people regrow hair on 5% topical minoxidil. It also explains why two people with identical hair loss using the exact same treatment can get completely different results.

For years there was no way to know in advance who would respond, so the standard approach was to commit to six months of daily use and see. This is beginning to change. A sulfotransferase enzyme test (sold as the Minoxidil Response Test) measures the enzyme’s activity in a few plucked hairs and can rule out non-responders before treatment. However, the test is not yet widely available in the UK as the evidence base is still small. If minoxidil is not working for you, there are several options worth considering:

• Tretinoin: Using a topical retinoid (or azelaic acid) can improve absorption which can turn a poor responder into a better responder. This is available in prescription compounded hair loss treatments.
• Microneedling: This can boost absorption of topical hair treatments and may stimulate the hair follicle through the skin’s healing response.
• Oral minoxidil: Switching to tablets bypasses the scalp enzyme, as the conversion then happens in the liver where sulfotransferase activity is much higher. Oral minoxidil is available by prescription-only and needs monitoring.
• Consider other causes: Hair loss often has more than one driver, so it is worth ruling out contributors like thyroid problems, low iron or scaring alopecias that need treating in their own right.

How to Use Minoxidil

The way you use minoxidil depends on the form. Topical minoxidil, whether the over-the-counter has fairly standard instructions. The way you use prescription compounded formulas will depend on the advice of your medical provider as depends on your individual condition and the composition of the treatment. There are however some general application tips that generally apply for topical minoxidil scalp and beard area:

• Application: Use on clean dry skin for optional minoxidil absorption.
• Amount & Frequency: For the over-the-counter liquid this is usually 1ml twice daily, 2-4 sprays or about half a capful of foam applied to the skin where the hair is thinning rather than onto the hair itself. Prescription formula amounts and frequencies will depend on the formula your provider prescribes. Generally, over-the-counter minoxidil requires twice daily use. A compounded formula combined with tretinoin is usually only once daily as the tretinoin prolongs minoxidil’s activity at the follicle.
• Absorption: Leave it to absorb for two to four hours before washing the area or layering other products.
• Safety: Always wash your hands straight after and keep away from pets or pregnant women.
• Be patient & consistent: As missed applications set you back and consistency matters more than anything else with minoxidil.

Oral minoxidil is taken differently. Starting doses are typically 0.25-5mg once daily and increased gradually, with women usually on lower doses than men). Because it works systemically it needs baseline blood pressure and heart rate checks plus ongoing monitoring.

Whichever form you use, the timeline is the same. Most people get an initial shed in the first few weeks, which is normal and a sign the treatment is working as minoxidil pushes resting hairs into the growth phase. Early results follow at three to six months, with maximum results around nine to twelve months for scalp and beard alike. Minoxidil works only for as long as you use it, so the gains fade gradually if you stop.

Side Effects of Minoxidil

The side effect profile is very different between topical and oral minoxidil. This is one of the main reasons topical is more popular. Topical minoxidil, in both its over-the-counter and compounded forms. As absorption is only minimal, so its side effects are mostly local:

• Scalp irritation: Itching, redness, dryness or flaking where you apply it. This is most often caused by the propylene glycol in liquid formulations rather than the minoxidil itself, so switching to a foam or a compounded propylene-glycol-free base usually resolves it. A small number of people develop a genuine allergy (contact dermatitis) to minoxidil itself.
• Unwanted facial hair: Minoxidil can cause hair to grow beyond the target area (hypertrichosis), most often on the cheeks or forehead in women. This usually comes from the product transferring or running onto the skin, and it reverses within a few months of stopping.
• The initial shed: A temporary increase in shedding in the first few weeks as minoxidil pushes resting hairs out to make way for new growth. It settles on its own and is a sign the treatment is taking effect.

These apply to both topical strengths, although higher-strength compounded formulas can irritate more. Adjusting the strength or base usually settles this. Systemic effects are possible if a lot is absorbed through the skin, but they are rare with topical use and far more relevant to the oral form.

Oral minoxidil works throughout the body, so it carries a wider set of risks. These are uncommon at the low doses used for hair loss but are the reason it needs monitoring:

• Generalised hypertrichosis: Increased hair growth across the body rather than just the scalp, commonly on the face, arms and legs. This is far more common than with topical and is the single most frequent reason people stop oral minoxidil.
• Cardiovascular effects: A drop in blood pressure, a faster heart rate and palpitations. Less often there is fluid retention and ankle swelling, and rarely fluid can collect around the heart (a pericardial effusion). This is why monitoring matters.
• Other effects: Dizziness, light-headedness and headaches, particularly when starting or increasing the dose.

Although there’s a lower risk, it is worth noting that it is still possible to experience systemic minoxidil side effects even with topical formulas. One point that applies to every form is that minoxidil is toxic to cats and dogs, so take care that pets do not lick the treated area or come into contact with the product. Always store it well out of their reach.

Who Can and Cannot Use Minoxidil?

Minoxidil is suitable for most adults with pattern hair loss or patchy beard growth. However, it is not for everyone. Below are some of the people that can not use oral or topical minoxidil:

• Pregnancy & breastfeeding: Minoxidil should be avoided in any form if you are pregnant, trying to conceive or breastfeeding. It should also be kept away from pregnant women and children, as it can transfer through skin contact.
• Age: It is for adults only and not used under the age of 18.
• An irritated or broken scalp: Do not apply topical minoxidil to broken, sunburnt or inflamed skin. Yous houdl also not use it on a scalp affected by another inflammatory skin condition as this increases and irritation.

Also, because the 2% and 5% topical is sold without a prescription, people often start it without anyone checking whether it is the right treatment. It is worth confirming the cause of your hair loss first, as minoxidil does nothing for shedding driven by iron deficiency, thyroid problems or a scarring alopecia, which need treating in their own right.

Oral minoxidil carries extra cautions that do not apply to the topical forms, because it acts on the whole cardiovascular system. The main limitations for using oral minoxidil include:

• Heart & blood pressure conditions: Anyone with a heart condition, low blood pressure or who takes blood pressure medication needs careful assessment first. This is because minoxidil lowers blood pressure and raises heart rate.
• Drug interactions: Minoxidil can interact with blood pressure medicines and some other drugs, so the prescriber needs a full list of what you take.
• Monitoring: It needs baseline and ongoing blood pressure and heart rate checks before and during treatment.

Because compounded formulas and oral minoxidil are available by prescription-only, your prescriber will weigh these factors. They will tailor the form, strength, base and any added actives to you.

How to Get Minoxidil in the UK

Minoxidil is prescription-only in every form except low-strength topical. As such, how you get it depends on what your hair loss or beard growth needs and individual health assessment:

• Over the counter: Topical minoxidil 2% and 5% (in products such as Regaine) can be bought from pharmacies and shops without a prescription. This is the only form available this way and only licensed for androgenetic hair loss.
• Private clinics & dermatologists: Higher-strength topical, any formula combining minoxidil with other actives and oral minoxidil are all prescription-only. You can usually only access them privately in the UK. A specialist compounding pharmacy makes up any bespoke topical formula to the doctor’s prescription.
• The NHS: Minoxidil is not usually funded on the NHS for pattern hair loss or beard growth, as these are considered cosmetic. The NHS may treat hair loss caused by an underlying medical condition but not routine female or male pattern hair loss.

At City Skin Clinic, we provide personalised topical minoxidil treatments for hair loss and beard growth where appropriate. The process works as follows:

• Consultation: You complete an online consultation form or book a video consultation with one of our doctors. You can share with them your hair or beard concern, medical history and any medicines you take.
• Assessment & prescription: Your doctor decides whether minoxidil is appropriate. If it is, they’ll design a bespoke compounded serum at the right strength with any complementary actives, along with a protocol to follow. If it is not the right fit, they will recommend a better option.
• Delivery & monitoring: A specialist compounding pharmacy makes up your treatment and delivers it to your door. The same doctor stays involved, monitoring your progress and adjusting future formulas. This is not a subscription service, so you reorder when you need to.

At City Skin Clinic, we are passionate about personalised hair care. We offer safe and effective custom treatments using ingredients like minoxidil, tretinoin, finasteride, dutasteride, spironolactone, caffeine and melatonin where appropriate through our online clinic. Our doctors treat hair loss in women and men, beard growth. To start your personalised plan, book a virtual video consultation or use our online consultation form. The journey towards great hair starts here.

This article is for informational purposes only and is not a substitute for medical advice, diagnosis or treatment. Always consult a qualified medical provider for any concerns or questions you might have.