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A Guide to Minoxidil Drug Interactions

If you’re experiencing hair loss, our guess is that you’re open to anything and everything that might help you stop and reverse the diminishing follicle count on your head. 

We get it — losing your hair isn’t something you want to do permanently, even if you can rock the shaved head look. 

But trying any and all hair loss treatments could cause bigger problems if you’re not careful about the safety and effectiveness of the treatments you’re using — not to mention the potential for negative interactions. 

Take minoxidil, for example. 

Minoxidil is a topical medication with benefits for people losing hair for just about any reason. And it’s generally considered safe with few serious side effects. 

But used the wrong way, with the wrong other medications, it could be dangerous. 

Hair Loss: Quick Facts

There’s such a thing as “normal hair loss.'' According to the American Academy of Dermatology (AAD), you actually lose about 100 hairs a day from regular shedding. 

Hair is lost normally as part of a three-phase cycle, made up of the anagen phase, the catagen phase and the telogen phase.

It breaks down like this: 90 percent of your hair should be in the growth (anagen) phase, with the remainder falling into the declining (catagen) phase and the resting (telogen) phase. 

About nine percent of your hair is in the telogen phase regularly, which is essentially the time when a follicle rests before beginning to grow again.

Hair loss is an interruption of these phases, either by making the telogen phase permanent, making the anagen phase difficult to reenter or by destroying the hair follicle beyond repair, causing it to cease functioning in the process.

Regrowing Hair with Minoxidil

Minoxidil (the generic version of Rogaine®) is a topical medication that benefits hair growth and regrowth by restarting the anagen phase in dormant follicles. 

We don’t fully understand the mechanism of how it promotes hair growth, but its results have been proven in significant amounts of research. 

One study found that over a 48-week period, minoxidil was able to boost hair growth and thickness by around 18 percent.

Minoxidil actually is sold in a topical and oral version, but in the U.S., only the topical is available. 

Topical minoxidil has been on the market since the ‘90s, and it’s typically sold in two strengths: 2% and 5% concentrations. Neither requires a prescription.

There are various versions on the market, and prices can vary. Brand-name Rogaine is typically sold around $30, while other versions may be more or less expensive. 

Our 5% Topical Minoxidil is an effective substitute at $15, and it’s safe and effective when used as directed.

Minoxidil Interactions

The good news is that, for the most part, minoxidil is considered safe to use, with minimal risk of negative drug interactions. 

Topical minoxidil is synergistic with other topical medications like tretinoin, which means that the two may actually increase each other’s benefits.

But that doesn’t mean you shouldn’t take routine caution when first beginning to use minoxidil. 

While no drug interactions have been reported, the possibility exists that absorbed topical minoxidil could interact with other drugs for hypertension, which could cause problems.

What has been demonstrated is that, when administered with diuretics or medications for hypertension, the blood pressuring lowering effects of minoxidil are increased, potentially to the detriment of the user. 

As such, minoxidil should be administered with caution, and you should let your healthcare provider know of other hypertension medications they might be taking. 

You should also let your healthcare provider know what medications you’re taking generally, including anything for blood pressure, as well as vitamins.

One specifically named medication is guanethidine, which shouldn’t be used concurrently with minoxidil because it may cause, “profound orthostatic hypotensive effects.”  

Other Medications For Hair Growth

According to the American Academy of Dermatology Association minoxidil is just one of the recommended products for regrowing hair. Another is finasteride.

Finasteride targets the hormone DHT, which is one of the primary causes of male pattern baldness (also known as androgenic alopecia). 

It blocks the hormone from forming, protecting your hair. 

Using finasteride daily can reduce DHT levels as much as 70 percent. 

Saw palmetto has also been shown to reduce DHT levels, particularly when combined with finasteride. 

Some other useful ingredients and compounds for hair loss (like saw palmetto) might also be part of the formulation of your shampoo.

Check out our What to Look For in a Men’s Hair Loss Shampoo guide for more.

Using Minoxidil For Hair Loss

Minoxidil may seem like a great treatment for people losing hair, and in many ways that may be true. 

But what we hope to have made clear here is that it can’t be used carelessly. 

Like any medication, minoxidil has the potential for serious issues (in this case, particularly for people on hypertension medications).

That means that the first step isn’t purchasing a batch of minoxidil, it’s actually talking to a healthcare professional. 

Healthcare professionals should be consulted first when you notice signs of hair loss — and we’re not just saying that as a disclaimer. 

Talking to your healthcare provider about hair loss symptoms is the smart thing to do, because it may uncover unusual causes of hair loss. 

Minoxidil may be beneficial in treating those, but your healthcare professional may also recommend lifestyle changes or address other underlying conditions that could be causing you to go bald. 

If you’ve already taken that step, or just need more information, we can help. 

Our DHT and male hair loss guide is a great place to learn about male pattern balding, and we’ve also put together a guide on how minoxidil and finasteride can work together to stop hair loss.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.