Does Phentermine Cause Hair Loss

You might expect side effects like nausea or headaches from an appetite suppressant like phentermine. But thinning hair might not be on your radar. 

Does phentermine cause hair loss? It’s a common side effect, but not for the reasons you might think. 

We explain phentermine hair loss below and list some helpful solutions for hair loss concerns due to phentermine or other causes.

Some of the more common side effects of phentermine include trouble sleeping and dry mouth. But is hair loss a side effect of phentermine?

Some people who take the weight-loss drug report phentermine hair loss, even though it’s not listed as a side effect.

(Possible Dr. Knox quote here about how taking phentermine may cause you to lose your appetite, so you may not be getting all the nutrients needed for hair growth.)

Getting fewer key vitamins and minerals could mess with your natural hair growth cycle, triggering hair loss.  

The following vitamin and mineral deficiencies can cause a type of hair loss known as non-scarring alopecia:

• B vitamins (such as biotin, folate and vitamin B12)

• Vitamin D

• Vitamin E

• Iron

• Zinc

Most people get enough of these vitamins and minerals from food. But taking an appetite suppressant might mean you’re eating less food — and getting fewer nutrients. 

Why Does Phentermine Cause Hair Loss?

Phentermine hair loss often happens because the medication suppresses your appetite, leading to a lack of hair-heathy nutrients. This type of hair loss (AKA telogen effluvium) causes excess hair shedding. 

Here’s how it happens:

Hair grows in three phases. 

• The anagen phase is when hair grows

• The catagen phases is when it stops growing

• The telogen phase is the rest period

Eventually, the exogen phase happens and hair starts to shed. 

A shorter telogen phase can cause your follicles to release hair sooner than typical, leading to excess shedding and hair loss.

Nutritional deficiencies can shorten the telogen phase. And phentermine can sometimes suppress your appetite so much that you’re not giving your body enough nutrients to support healthy hair growth. 

Will My Hair Grow Back After I Stop Taking Phentermine?

Is hair loss from phentermine permanent? Telogen effluvium is usually temporary, so phentermine hair loss probably is too. 

When you stop taking the medication or focus on eating more nutrient-dense foods, you’ll probably start shedding less and see improvements in hair growth. 

A 2020 study in the journal Cureus notes that once you treat the underlying cause of telogen effluvium, hair growth often resumes.

If you’re experiencing male pattern baldness (androgenetic alopecia), your hair loss could become permanent if you don’t act quickly. Learn more in our guide to male pattern baldness.

Phentermine is in a class of amphetamine-like drugs called anorectics. Doctors prescribe this weight loss medication to people already attempting to lose body weight through healthy nutrition and exercise. 

Until the recent arrival of Ozempic and other newer weight loss drugs, phentermine was one of the go-to medications for weight loss.

For those already implementing healthy eating habits, phentermine can help speed up the weight loss process by decreasing appetite.

While phentermine may not lead to rapid weight loss, it’s effective at helping some people reduce their body mass.

The medication is available in tablet or extended-release capsule form. 

Keep in mind, it’s not a long-term treatment. Healthcare professionals usually prescribe it for three to six weeks. In some cases, a doctor might prescribe it for up to 12 weeks or longer. 

Common Side Effects of Phentermine

Is phentermine hair loss a side effect? The drug label doesn’t list hair loss as a potential side effect.

Phentermine side effects can include:

• Weight loss

• Vomiting

• Constipation

• Diarrhea

• Dry mouth

• Unpleasant taste in your mouth

Serious side effects can include:

• High blood pressure

• Heart palpitations

• Tremors

• Insomnia

• Shortness of breath

• Chest pain

• Swelling of the legs

If you notice any of these symptoms when taking phentermine, seek medical attention right away.

Phentermine Drug Interactions and Considerations

Before you start taking this weight loss medication, let your healthcare provider know about previous allergic reactions you’ve had to medications or any medical conditions you have. 

You’re at a crossroads: You want to reach your weight loss goals and keep a full head of hair. The good news is you can have both.

If you’re taking phentermine and notice excessive hair loss or hair thinning, the first thing to do is seek medical advice from your healthcare provider. 

“When I see patients for hair loss I start with questions like how long ago did your hair loss start, are you losing hair in certain areas or throughout the scalp, are you having any areas of complete hair loss, etc. I also do a thorough scalp exam,” Dr. Beasley says. “This helps me determine the cause of their hair loss so we can have a discussion on why they are losing hair and what treatment options we have available to stop or potentially reverse their hair loss.”

Anytime you’re on medication and notice strange symptoms, it’s vital to bring them up. That way, your provider can keep an eye on them and advise you on what to do.

Here are some options that might help with phentermine hair loss, from lifestyle changes to hair loss treatments.

Eat More Hair-Friendly Foods

It’s likely not the phentermine itself causing hair loss. But the reduction in appetite could lead to nutrient deficiency-related hair loss. 

So how do you reverse phentermine hair loss? One way is to consume more nutrient-rich foods that support hair growth.

(Possible Dr. Knox quote here about key nutrients for hair health)

Zinc and iron are two essential minerals for healthy hair growth. Eating crab, cashews and oatmeal can help you get more zinc. For iron, try to eat more spinach, lean meats and seafood or take an iron supplement.

Biotin is another nutrient needed for hair growth. It’s found in foods like bananas, eggs and milk.

Another source? Hims biotin gummies, which also contain vitamin D. 

Try Hair Loss Medication

Minoxidil is a topical treatment that’s FDA-approved to treat hair loss. It’s available in liquid or foam formulas. And you don’t need a prescription to use it. 

Minoxidil stimulates hair follicles to enter the growth (anagen) phase. Plus, it boosts blood flow to the scalp, bringing nutrients to your hair follicles and stimulating growth.

Another option is finasteride. You can take it orally in tablet form or apply it topically. Finasteride lowers dihydrotestosterone (DHT), a hormone that can cause hair loss when there’s too much of it in your body.

Better yet, combine these two science-backed medications with a two-in-one treatment like our topical finasteride & minoxidil spray.

Add a Hair Loss Shampoo to Your Routine

Working a nourishing formula shampoo into your hair care routine is another helpful strategy. 

The thickening shampoo from Hims contains saw palmetto, a natural ingredient thought to help with hair loss by blocking DHT.

When you take a medication like phentermine, the goal is weight loss, not hair loss.

So why does phentermine cause hair loss? Let’s recap:

• Phentermine is a weight loss medication that suppresses appetite. Doctors usually prescribe it alongside a balanced diet and regular exercise.

• Eating less can increase your risk for a nutrient deficiency. If you notice hair loss after you start taking phentermine, it might be because you’re not getting enough of certain nutrients — and a nutrient deficiency could lead to hair loss.

• Telogen effluvium is usually reversible. Lifestyle changes, like eating more foods rich in hair-growth nutrients can help address nutrient deficiencies.

• Hair loss medications can help too. Hair loss medications can help with temporary phentermine hair loss or genetic male pattern baldness. 

When navigating hair loss while taking phentermine, it’s best to connect with a healthcare provider to discuss your options.

Hims offers online consultations, so you can get hair loss advice from home at a time that fits your schedule. Get started today!