Stimulating Hair Growth: What Really Works for Hair Loss?

Many people look for ways to stimulate hair growth. This is understandable. Hair loss can lead to insecurity and often significantly impacts how someone feels. Online, you'll find many promises: shampoos, hair loss pills, supplements, vitamins, oils, and treatments that claim to provide "new hair growth."

However, not everything works equally well. Some treatments are well-researched. Other products sound logical but have little evidence. In this article, we explain what is known about stimulating hair growth for hair loss. We will look at scientifically backed remedies, such as minoxidil, finasteride, finasteride spray, and widely discussed options like biotin, vitamins for hair loss, supplements, PRP, and low-level laser therapy. We will not consider cosmetic lotions. These may be suitable as supplementary care or to keep the scalp calm but are not considered a treatment.

First: why does hair fall out?

Hair does not grow continuously. Each hair follicle goes through a cycle. This cycle consists of a growth phase, a transition phase, a resting phase, and a shedding phase. The growth phase is called the anagen phase. For scalp hair, this can last several years. This is followed by a short transition phase, the catagen phase, and then a resting phase, the telogen phase. Eventually, the hair detaches and falls out.10

Some hair loss is therefore normal. On average, people lose hair daily. This is part of the normal hair cycle. It becomes different when the balance is disturbed. Then fewer hairs grow back, hairs become thinner, or more hairs simultaneously shift to the resting or shedding phase.

In androgenetic alopecia, also known as hereditary hair loss, genetic predisposition and hormones play an important role. Dihydrotestosterone, or DHT, in particular, can cause miniaturization in sensitive hair follicles. The hair follicle then shrinks and produces progressively thinner hairs.2,3

Can you really stimulate hair growth?

Yes, for certain types of hair loss, you can. Especially with androgenetic alopecia, there are treatments that can slow down hair loss and, for some people, also stimulate hair growth.

The best-researched treatments are:

• topical minoxidil, such as minoxidil lotion or minoxidil foam (available over-the-counter);
• finasteride pills, for men with androgenetic alopecia (by prescription from a doctor);
• finasteride spray (currently not available in the Netherlands);
• in specific situations: off-label treatments* such as a low dose of minoxidil tablets or dutasteride (by prescription from a doctor).

Other options, such as vitamins, biotin, supplements, PRP, and laser therapy, can sometimes play a supplementary role. However, the evidence is often less strong than for minoxidil and finasteride.

Minoxidil: one of the best-researched agents to stimulate hair growth

Minoxidil is one of the most well-known hair loss treatments. It was originally developed as a high blood pressure medication. Later, it was noticed that some users experienced extra hair growth. Minoxidil was then further investigated as a treatment for hair loss.

Topical minoxidil, meaning minoxidil applied to the scalp, has been well-researched for androgenetic alopecia. Both 2% and 5% minoxidil show effectiveness in studies.1,2,3

Minoxidil likely works in multiple ways. It can prolong the hair's growth phase and stimulate hair follicle activity. The exact mechanism of action is not yet fully known. However, it is clear that minoxidil primarily works when used long-term and consistently.10,12

Minoxidil lotion or minoxidil foam: which is better?

Many people ask: what is better, minoxidil lotion or minoxidil foam? The honest answer is: it depends on your scalp, your preference, and how well you can use the product daily.

Minoxidil lotion is liquid. This often allows for precise application to specific areas. Some people find this pleasant, for example, for receding hairlines or a clear zone on the crown.

Minoxidil foam, also called minoxidil mousse, is less liquid. Foam often absorbs quickly and usually does not contain propylene glycol. This can be comfortable for people who are sensitive to certain excipients. Propylene glycol can cause irritation, itching, or redness in some users.

Both forms can work, provided they are used correctly and consistently. The best choice is often the form that someone can maintain for the longest.

Are you unsure which form suits you best? Check out the differences between minoxidil foam and lotion.

When do you see results from minoxidil?

Minoxidil does not work immediately. This is important to know. Many people stop too early because they don't see a clear difference after a few weeks.

In practice, we usually assess the effect only after 3 to 6 months of consistent use. Sometimes further improvement is possible after that. When starting, temporary increased hair shedding may occur. This is called shedding. This can be alarming, but it is sometimes part of the transition of hairs to a new growth phase.

If you stop using minoxidil, the achieved results usually disappear again after a few months. Therefore, minoxidil is not a short course but a maintenance treatment.3,6

Finasteride: DHT blocker against hair loss in men

Finasteride is a medication used for male androgenetic alopecia. It primarily inhibits the enzyme 5-alpha-reductase type II. This enzyme converts testosterone into DHT. DHT plays an important role in the thinning of hair in hereditary hair loss.2,3

The usual dosage for male androgenetic alopecia is 1 mg per day. Studies and meta-analyses show that finasteride works better than placebo in men with androgenetic alopecia.7

Finasteride can slow down hair loss and promote regrowth in some men. The product is especially suitable when DHT-sensitive miniaturization plays a clear role.

Finasteride can cause side effects. These include sexual side effects, mood disorders, and reproductive considerations. These side effects do not occur in everyone, but they must be discussed beforehand. In women, finasteride is sometimes prescribed off-label. This means that its use does not fall within the officially approved indication. Finasteride should under no circumstances be used during pregnancy due to the risk of harm to the unborn child. Women who are pregnant, planning to become pregnant, or could become pregnant should always discuss this with their doctor beforehand.

Finasteride spray: local treatment with lower systemic exposure

In addition to tablets, there is also topical finasteride, such as finasteride spray. This spray is designed to deliver finasteride locally to the scalp. The goal is to maintain its effect on the hair follicle, with less exposure (and therefore potentially fewer side effects) in the rest of the body.

In several European countries, finasteride spray is registered for men with hereditary hair loss (androgenetic alopecia).18 In the Netherlands, this is yet to happen. The study with local finasteride spray showed that the spray worked better than placebo. The effect was comparable to oral finasteride 1 mg. At the same time, the amount of finasteride in the blood was more than 100 times lower than with oral finasteride19.

Oral minoxidil: minoxidil tablets for hair loss

There is increasing attention to minoxidil tablets for hair loss. These are tablets with a low dose of minoxidil. Doctors sometimes use this off-label for various forms of hair loss, such as hereditary hair loss. Off-label use means that the product is not officially approved for hair loss, but a doctor may prescribe it in some cases.5,20

The dose varies per person. Women usually receive a lower dose than men. In studies on women, for example, dosages of 0.25 mg and 1 mg per day have been investigated.21 In men, dosages of 2.5 mg and 5 mg per day have been investigated, among others.22,23

Minoxidil tablets can help some patients, but they are not harmless supplements or vitamins. It is a medicine. Possible side effects include extra hair growth on other parts of the body, fluid retention, headaches, swollen ankles, heart palpitations, and effects on the heart and blood vessels. Therefore, minoxidil tablets should only be used under the supervision of a doctor.5,22

Dutasteride: stronger than finasteride, but off-label for hair loss

Dutasteride is similar to finasteride. Both drugs lower DHT. DHT is a hormone that can cause hair follicles to shrink in hereditary hair loss. This makes hair thinner and more likely to fall out.

Dutasteride often inhibits DHT more strongly than finasteride. In some studies, dutasteride therefore appears to work potentially better for men with hereditary hair loss.6,7

Use for hair loss is often off-label in Europe. This means that a doctor can prescribe it, but hair loss is not among the officially approved indications for the medication.

Therefore, a doctor must carefully assess whether dutasteride is appropriate. The patient must also receive a clear explanation of the potential benefits, side effects, and uncertainties.

Combining minoxidil and finasteride

Sometimes it can be extra effective to combine treatments. Minoxidil and finasteride work in different ways.

Minoxidil helps stimulate hair growth. It can ensure that hairs stay in the growth phase longer. Finasteride works differently. This agent lowers DHT. DHT is a hormone that makes hair follicles smaller in many men with hereditary hair loss. This makes hair thinner and can eventually lead to hair loss.

Because minoxidil and finasteride work in different ways, they can sometimes complement each other. Studies on the combination of topical minoxidil and topical finasteride show that this combination can yield better results than minoxidil alone.8

However, it is important to consider which product is used. There is a difference between registered products and compounded preparations from the pharmacy or another provider. For compounded products, the effectiveness has not been investigated. This depends on the composition, the base of the product, the strength, and how well the active ingredient reaches the hair follicles.

PRP for hair loss

PRP stands for platelet-rich plasma. In Dutch, this means: plasma with many platelets.

For a PRP treatment, the doctor first takes some blood. That blood is then processed. This creates a liquid with many platelets. This liquid is then injected into the scalp.

The idea is that substances from the platelets can support the hair follicles. Some studies show that PRP can improve hair density.25,26

However, the evidence is less strong than for treatments such as minoxidil and finasteride. This is also because PRP is not performed in the same way everywhere. The method of drawing blood, processing it, and injecting it differs per clinic. The number of treatments and the maintenance schedule also differ.

PRP can therefore sometimes be a supplementary option. It is not a substitute for treatments whose efficacy has been better researched (such as minoxidil or finasteride).

Low-level laser therapy: light and laser for hair loss

Low-level laser therapy is often abbreviated as LLLT. This treatment uses red light or near-infrared light. There are devices for use in clinics, as well as devices for home use, such as laser helmets or laser combs.

Some studies show that LLLT can improve hair density in hereditary hair loss.²⁴

However, the evidence is less strong than for minoxidil and finasteride. Not every device is the same. The strength of the light, the number of lights, the treatment time, and the number of treatments per week can vary. Therefore, the results of studies cannot simply be translated to every device sold online.

LLLT can therefore sometimes be a supplementary treatment. It is not a standard replacement for minoxidil or finasteride.

Vitamins and hair loss: do supplements make sense?

Many people look for vitamins for hair loss. Think of vitamin D, biotin, zinc, iron, selenium, or multivitamins. It is important to look at this critically.

Vitamins and minerals are important for the body and thus also for hair. But that does not mean that taking extra pills helps. Supplements are especially useful when there is a deficiency or an increased risk of a deficiency. Think of iron deficiency, low ferritin levels, vitamin D deficiency, zinc deficiency, a strict diet, malabsorption, heavy menstruation, or certain medications.9,14

In people without a deficiency, there is no good scientific evidence that supplements work for hair loss.

Vitamin D for hair loss

A vitamin D deficiency is sometimes seen in studies in people with hair loss. This does not automatically mean that taking vitamin D helps stimulate hair growth.

Supplementing vitamin D is especially logical if there is truly a deficiency, or if there is a clear suspicion of one.

With telogen effluvium, diffuse hair loss often occurs. This means that hair thins all over the scalp. This form of hair loss can sometimes resolve on its own. This makes it difficult to know for sure whether improvement comes from vitamin D or from natural recovery.

The practical message is: only supplement vitamin D in case of a deficiency or clear risk factors.

Iron (ferritin) and zinc for hair loss

Iron is important for rapidly dividing cells. This also applies to cells in hair follicles. Therefore, an iron deficiency or low ferritin levels can play a role in diffuse hair loss. Ferritin is a measure of the body's iron stores.

Iron deficiency is more common in people with heavy menstruation, a vegetarian or vegan diet, fatigue, or other risk factors. In these situations, it may be useful to discuss this with a doctor and possibly have blood tests done.9,14

A zinc deficiency can also be associated with hair loss, brittle hair, and thinning hair. Zinc tablets are especially helpful when there is a real deficiency. With normal zinc levels, it is less clear whether extra zinc helps against hair loss.9,14

Biotin for hair loss: popular, but often overestimated