Minoxidil: tablet or solution?

You’ve been using the solution for months, morning and evening, and someone tells you about a tablet that’s “much easier”. Or your dermatologist brings it up at an appointment. Same name, minoxidil, but a form you’ve never seen on a pharmacy shelf for hair. Is it the same treatment, just more convenient?

Not quite. The molecule is the same, but it doesn’t take the same path through the body, it doesn’t have the same licence and it doesn’t carry the same side effects. Here’s what the official product information and the studies say.

One molecule, two routes

The solution goes on the scalp and works where it’s applied. Only a small amount gets through the skin: according to the product information for a 5% solution, 1.7% on average of the amount applied reaches the bloodstream, ranging from 0.3% to 4.5% depending on the person².

The tablet is swallowed. Its product information states that at least 90% of the dose is absorbed by the gut, quickly, then broken down mainly by the liver¹. So it circulates through the whole body, not just under your hair.

That difference explains everything else: the licence, the side effects and the monitoring.

Not the same licence

The solution is licensed for hair loss. The leaflet for a 5% solution sold in France restricts it to adult men with moderate androgenetic alopecia². The French Society of Dermatology (SFD) describes it as the topical treatment most often offered for this kind of hair loss³.

The tablet is licensed for something else. Its product information restricts it to severe high blood pressure after other treatments have failed, and says it shouldn’t be a first-line prescription¹. For hair loss, a doctor can prescribe it at a low dose, but off-label: a use the licence doesn’t cover. An international consensus of 43 hair specialist dermatologists from 12 countries describes it as an increasingly popular off-label treatment⁴.

In the UK, the British Association of Dermatologists (BAD) lists the solution among licensed treatments and low-dose tablets under “other treatments”⁵.

What the studies show

Dermatologists don’t all agree. The Spanish Academy of Dermatology, in a consensus of 34 specialists, considers low-dose tablets more effective than the solution⁷. The BAD is more cautious: recent research has shown that they may be at least as effective as the solution, with few side effects, “in certain scenarios”⁵. These are expert opinions, not measurements.

The most robust head-to-head comparison comes from a Brazilian trial published in 2024. Men aged 18 to 55 with androgenetic alopecia were randomly assigned either minoxidil tablets with a placebo solution, or minoxidil solution with a placebo tablet, for 24 weeks. Neither they nor the doctors knew who was taking what⁶.

The result: on the main outcome, hair density at the front and on the crown, the tablet did no better than the solution. On photographs, it did better on the crown, but not at the front⁶. The limits are clear: 90 men enrolled, 68 completed the study, a single clinic, six months of follow-up, no women⁶.

For what happens in the first few weeks and how long to wait before drawing conclusions, there’s an article on when to judge oral minoxidil, and another on how long the solution takes.

Side effects

With the solution, side effects mainly affect the scalp: dryness, redness, scaling or itching⁵. Hair can also grow elsewhere, on the face for instance. The leaflet can’t estimate how often, and for that reason advises against the 5% solution for women².

With the tablet, side effects concern the whole body. A 2025 Spanish review brought together the studies on low-dose oral minoxidil⁸:

• extra hair on the face or body (hypertrichosis): the most common effect, in 15.1% of the 1,404 patients in the largest study⁸;
• a fast heart rate or palpitations, in 0.9% to 4% of patients, mostly in the first three days, usually mild and short-lived⁸;
• dizziness, in 1% to 1.7% of patients, mostly in the first week and more often in women⁸;
• fluid retention, with swollen ankles or face, in 1.3% to 10% of patients, usually around the second month⁸;
• headaches, in 0.4% to 9% of patients depending on the study⁸.

Largest study cited in the review by Jimenez-Cauhe et al., 1,404 patients. Figures vary widely from one study to another.⁸

In the Brazilian trial, this extra hair affected nearly one man in two on the tablet (22 out of 45)⁶. Serious effects are rare. The review reports 12 serious cases out of about 1,700 prescriptions in one series, mostly due to pharmacy compounding errors that produced a dose 10 to 100 times too strong⁸.

Heavier shedding in the first few weeks is possible with both forms. For the tablet, the review puts it at 16% to 32% of patients, and believes that figure is an underestimate⁸. It’s covered in detail in early shedding with oral minoxidil and in shedding in the first weeks with the solution.

Contraindications and monitoring

The tablet’s product information lists its contraindications: a recent heart attack, phaeochromocytoma (a rare tumour of the adrenal glands), pulmonary hypertension caused by a narrowed mitral valve, and allergy to the product¹. It isn’t recommended during pregnancy or for women of childbearing age not using contraception, and it passes into breast milk¹. The solution is contraindicated during pregnancy³.

Dermatologists add situations where low-dose tablets aren’t advised: heart failure, severe heart valve disease, advanced kidney disease⁸, or a history of heart rhythm problems⁷. They recommend caution over the age of 65⁷.

For someone without a significant medical condition, the review and the Spanish consensus don’t consider regular tests necessary during treatment⁷⁸. Baseline checks and follow-up are up to the doctor: the international consensus devoted a section to them⁴. It’s also up to your doctor to say whether either form suits you. To prepare for that appointment, here are the questions to ask your doctor.

What happens if you stop?

Solution or tablet, the principle is the same: the BAD points out that treatments for androgenetic alopecia only work for as long as you keep taking them⁵. The SFD calls it a suspensive treatment: when you stop, the hair loss resumes³. As for blood pressure, the tablet’s product information says there is usually no rebound effect when it’s stopped¹.

Tracking the effect with photos

Whether your doctor suggests the solution, the tablet or something else, the next question will be the same: is anything changing on your scalp? The mirror is a poor judge. Light, angle and styling vary, and a slow change is invisible from one day to the next.

Comparable photos do better: same room, same light, same distance, once a week. With Calvap, each area of your scalp is photographed the same way, with the previous photo overlaid so you can line up the shot. Your journal keeps the date you started treatment and what you notice, including facial hair or swollen ankles. At your appointment, you show your doctor dated photos and precise notes.