Risks / Side Effects

Analyzing the Minoxidil Risk Categories

Are you allergic to minoxidil or other drugs that cause health reactions?

If you are already using minoxidil, have you experienced any side effects or allergic reactions?

If you already are taking minoxidil and it is causing problems, then naturally you should stop. (You should also stop hitting your head on a wall if this causes headaches.) If other drugs cause health problems, you may be sensitive to minoxidil as well.

Have ever had heart, kidney, liver or scalp disease?

Are you taking any medications for high blood pressure?

Do you have a sunburned or irritated scalp?

Minoxidil originally was sold as an oral medication to treat hypertension. Even when used topically, minoxidil could affect heart rate, heart rhythms and blood pressure. It also could affect the normal operation of kidneys and liver. If you have a scalp disease, then using a powerful scalp medication is not recommended. Also, a sunburned or irritated scalp may absorb excessive levels of minoxidil.

Will you be experiencing prolonged exposure to sunlight without protective clothing, sunglasses and sunscreen?

Minoxidil can make skin more sensitive to sunlight, so users should take the appropriate precautions or stop using the drug.

Will you use minoxidil more often than twice per day?

The directions on minoxidil are very clear: Use only the recommended amount and apply no more than twice per day. Applying minoxidil more often, even if you missed an application on a previous day, can cause adverse reactions. Increasing dosages beyond recommended limits is dangerous for any drug, including minoxidil.

Are you willing to continue using minoxidil indefinitely?

If you don’t want to or can’t afford to continue using minoxidil for the foreseeable future, you probably shouldn’t start. Not only will hair growth cease when you stop using minoxidil, but the hairs that grew after you started using the drug will fall out.

Are you pregnant, or do you plan to become pregnant while using minoxidil?

Are you breastfeeding?

Should you use minoxidil during pregnancy or while nursing? Safe answer: no. More complicated answer: probably not. The FDA has placed minoxidil in Pregnancy Category C: “Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.”

Do you have a pet cat or rat that may be exposed to your minoxidil?

Minoxidil is highly toxic to both cats and rats. If they get into your supply, they could die and you could run out of minoxidil.

So if don’t have heart disease, aren’t pregnant, and your cat already ran away, are you a potentially safe user of minoxidil? Before answering, consider the possible side effects, both common and uncommon. If side effects occur while using minoxidil, and they affect your health is affected, consider stopping treatment.

The following information about side effects is from the National Institutes of Health

Common side effects of minoxidil

• Itching, redness or irritation at the treated area

• Burning or irritation of the eye

• Alcohol in minoxidil preparations may dry the scalp, resulting in dandruff

Less common side effects

• Unwanted hair growth elsewhere on the body

• Hair loss (in addition to the normal “shedding” that occurs prior to hair growth)

Severe allergic reactions

• Rash, hives, itching, difficulty breathing, tightness in the chest, swelling of the mouth, face, lips or tongue

• Chest pain, dizziness, fainting, fast heartbeat, sudden and unexplained weight gain, swollen hands or feet

Minoxidil is a powerful medication, and the side effects identified as “common” are indeed common. If you’re lucky, they won’t occur, but don’t be surprised. Many users report that their scalps sometimes get slightly sore and irritated when they rub minoxidil into their tender scalps – and then leave it there for 4 hours. Using the “no pain, no gain” approach, they tough it out and continue the treatments. But if the effects are too severe, the minoxidil should be washed out. Those whose scalps are too irritated may decide that the pain and skin damage aren’t worth using minoxidil at all. 

Accidentally getting minoxidil in your eyes is to be avoided at all costs. This is less of a side effect than a test of your balance and dexterity. Can you hold your head still at the right angle to prevent drippage? Are you using towels in the right spots? If not, switch to the foam.

Other factors to consider

• Minoxidil is for external use only. Do not swallow or get into your eyes, nose or mouth. Do not apply dressings, bandages, cosmetics lotions or other skin medications to the area being treated.

• Tell your doctor about any prescription or nonprescription medicines, as well as vitamins, minerals or other dietary supplements.

• The use of minoxidil by children or adults above age 65 has not been studied.

• Minoxidil can stain clothing, hats or bed linen if your hair or scalp is not completely dry after using the preparation.

• A doctor should check your progress during regular visits.

Manufacturer warnings for Rogaine Foam

According to the manufacturer, you should not use Rogaine Foam if any of the following are true:

• You are allergic to any ingredient in Minoxidil Foam;

• You are a woman;

• You only have hair loss toward the front of your head (e.g., a receding hair line);

• You have no family history of hair loss or you don’t know the reason for your hair loss;

• You have sudden or patchy hair loss;

• Your scalp is red, inflamed, infected, or painful;

• You are using other medicines on your scalp.