Minoxidil is one of the most common hair loss treatments for both men and women. 

However, some users may experience skin irritation, itching, or an allergic reaction after using topical minoxidil formulation on their scalp. These side effects may not actually be caused by minoxidil but by an inactive ingredient in the formulation—which is alcohol.

We’ll explore the possible side effects of alcohol in minoxidil and the benefits, risks, and efficacy of a low-alcohol formulation compared to a regular one.

What is Minoxidil?

Minoxidil is a medication typically prescribed for treating conditions related to hair loss.

It is currently FDA-approved as a hair loss treatment in men and women and is widely prescribed for treating the most common type of hair loss known as androgenetic alopecia. Androgenetic alopecia is more commonly called male pattern baldness in men or female pattern hair loss in women [1].

This type of hair loss is typically associated with your genes and hormones and typically involves thinning hair at the crown and top of your scalp.

Minoxidil helps tackle this condition by slowing down the balding process and stimulating hair regrowth.

You can easily purchase topical minoxidil from a pharmacy without a prescription or consult a doctor who may prescribe you oral minoxidil. Both oral and topical minoxidil can be used to treat hair loss.

How Does Minoxidil Work?

Though experts are entirely sure of the exact mechanism of action of minoxidil, research suggests that minoxidil helps by shortening the resting phase of hair (the telogen phase) and lengthening the growth phase (anagen phase) [2].

Minoxidil is also thought to enlarge hair follicles and enhance the supply of blood and nutrients to the scalp by dilating blood vessels. This may help to support hair growth.

Is There Alcohol in Minoxidil?

Yes, you’ll find that many minoxidil products contain alcohol.

The main vehicles utilized in minoxidil topical formulations include water, alcohol, and propylene glycol [3].

Drug-delivery vehicles are substances that help improve efficacy, safety, or convenience during the process of delivering the medication to targeted areas.

Alcohol is typically included to help speed up drying when minoxidil is applied to the scalp [4]. This also makes the application process more manageable and less of a mess.

That means most minoxidil products, including topical solutions and sprays, contain alcohol. But this isn’t surprising since alcohol is a common ingredient in shampoos and other hair care products.

What Percent Alcohol is Minoxidil?

In general, minoxidil topical formulations typically have an alcohol content of around 30-60%. Of course, this varies from brand to brand and may also depend on whether you opt for a foam or liquid formulation.

What Are the Effects of Alcohol on the Scalp?

Alcohol can dry out your scalp, and this may lead to skin irritation, redness, itching, and flaking of the skin. So in some cases, side effects from using minoxidil products may actually stem from the alcohol within the formulation rather than the medication itself [5].

Not everyone who uses minoxidil will experience such side effects, as they mainly affect people sensitive to alcohol-containing formulations [3].

Those who experience do such side effects may be less adherent to their treatment regimen. And if the treatment instructions are not followed as given (i.e., using minoxidil less often than recommended), this can affect how effective the medication is and how quickly you’ll notice results [3].

What is Low-Alcohol Minoxidil?

Low-alcohol minoxidil is specifically designed to contain a lower percentage of alcohol. This formulation may be gentler on the scalp and less likely to cause skin irritation or redness.

Low-alcohol minoxidil may also help maintain your scalp’s hydration and reduce your risk of scalp dryness, itching, or redness caused by alcohol [3].

Hence, low-alcohol minoxidil may be suitable for those with a sensitive scalp and those with a sensitivity towards alcohol.

Is Low-Alcohol Minoxidil Less Effective?

Research studies suggest that a higher percentage of alcohol in the formulation may help improve how well the medication penetrates the skin.

For instance, a study found that as the concentration of alcohol in the minoxidil solution decreased, the penetration of the medication into the skin also decreased [6].

This means that a lower-alcohol minoxidil formulation may deliver the medication less efficiently than a higher-concentration one. That’s simply because alcohol plays an important role in promoting minoxidil penetration into the scalp [6].

Though research has discovered that alcohol helps to enhance minoxidil penetration, there isn’t much research investigating how significantly this affects efficacy and minoxidil treatment outcomes.

Nonetheless, there is some anecdotal evidence supporting the efficacy of low-alcohol minoxidil in treating hair loss.

Is Low-Alcohol Minoxidil Less Likely to Cause Side Effects?

Yes, research has found that low-alcohol minoxidil may help improve the scalp’s hydration when used in place of a regular minoxidil formulation. Based on study results, low-alcohol minoxidil can reduce the incidence of adverse effects, including any redness, irritation, and itchiness of the scalp.

Essentially, low-alcohol minoxidil is generally better tolerated compared to its higher-alcohol counterpart, as it is less likely to dry out your scalp and cause skin irritation [7].

Nonetheless, purchasing a low-alcohol minoxidil formulation does not automatically guarantee that the product will be safe for you.

The medication itself may also lead to side effects of its own and may not be suitable for certain groups of people. For instance, minoxidil may not be suitable for pregnant or breastfeeding women, and they should seek professional medical advice before commencing minoxidil treatment.

Is There Alcohol-Free Minoxidil?

Yes, alcohol-free minoxidil does exist for those who are not able to tolerate alcohol-containing formulations. But alcohol-free minoxidil can be much harder to find compared to regular and low-alcohol minoxidil. There isn’t much research investigating the efficacy of alcohol-free minoxidil, either.

Nonetheless, alcohol-free minoxidil is less likely to cause skin irritation or scalp dryness and may help preserve your scalp’s natural oils and hydration better than conventional formulations.

What About Propylene Glycol in Minoxidil?

Propylene glycol is another common inactive ingredient you’ll see in minoxidil products. Propylene glycol also serves as a drug-delivery vehicle that helps improve minoxidil penetration into the skin and enhances its solubility in a liquid formulation.

Nonetheless, some people who use liquid minoxidil containing propylene glycol experience side effects. Some of the most common side effects include scalp irritation, a burning sensation upon application, itching, and redness [3].

This is further evidenced by some research suggesting that side effects are more common in minoxidil 5% compared to minoxidil 2%. This may be due to the higher concentration of propylene glycol in minoxidil 5% needed to solubilize the medication [3].

If you have experienced scalp irritation, redness, or itching from utilizing a liquid minoxidil product, you may be sensitive to the propylene glycol inside the product. In this case, you may opt for propylene-glycol-free minoxidil as foam. Research has investigated the efficacy of minoxidil foam, which is also shown to be safe and effective for treating androgenetic alopecia. 

Fortunately, propylene-glycol-free minoxidil foam is widely available on the market and much easier to find than alcohol-free formulations [8].

Final Takeaway: Is Low-Alcohol Minoxidil Better?

Low-alcohol minoxidil is less likely to cause side effects such as scalp irritation, redness, burning, or itching compared to regular minoxidil formulations. However, there isn’t much research comparing the efficacy of low-alcohol minoxidil to conventional minoxidil.

If you’re unsure about which formulation suits you best, it’s safest to seek the advice of a healthcare professional.