Hair Loss After Weight Loss: Causes, Risks & Prevention

Weight loss can severely improve your health but may have unexpected side effects. Along with having to buy new clothes and field questions from acquaintances about “how you did it,” you might experience physical side effects, like loose skin, feeling cold or even hair loss with weight loss. 

Rest assured, you shouldn’t lose hair after dropping a pants size or two.

Hair loss with weight loss is usually seen in people who shed significant weight or have a nutritional deficiency. The latter means you lack certain vitamins and nutrients, a potential effect of extreme dieting (looking at you, crash diets) or severely restricting calories.

Read on to learn more about the connection between hair loss and weight loss. We’ll also go over what you can do to prevent or treat hair loss from weight loss.

Why Hair Loss After Weight Loss Happens

The American Academy of Dermatology notes that losing 20 pounds is a stressor that can cause hair loss. But why does this happen?

Rapid weight loss can trigger a form of hair loss called telogen effluvium. It happens when you go through extreme bouts of stress, which disrupts the natural hair growth cycle.

Stress can cause hairs in the growing phase (anagen phase) of the hair growth cycle to suddenly enter the telogen phase (resting phase) — meaning hair stops growing for months.

Then, those hairs shed from the follicle, causing sudden hair loss. You usually notice the hair shedding a few months after you encounter the stressor.

There are four main reasons why weight loss might lead to hair loss:

• Diet and nutritional deficiencies

• Bariatric surgery-related hair loss

• Illnesses

Let’s dive into each issue below.

Diet and Hair Loss

Losing a bit of weight due to dietary changes probably won’t affect your hairline. But there is a link between diet and hair loss.

If you take dieting or calorie restriction to the extreme, you might be at risk of developing a nutritional deficiency.

Plenty of research shows a link between a poor diet and hair loss. Your body needs certain nutrients in order to produce hair cells, and when you lack those nutrients, you might lose hair.

Specifically, the following nutritional deficiencies are associated with hair loss:

• Iron

• Niacin

• Zinc

• Fatty acids

• Selenium

• Vitamin D

• Vitamin A

• Vitamin E

• Folic acid

• Amino acids

• Biotin

And it’s not just about micronutrients. Your hair is primarily made up of protein.  For healthy hair growth, you need to make sure you’re getting enough protein. A protein deficiency may lead to hair thinning and hair loss.

Restrictive diets often mean you’re not getting all the essential nutrients you need for healthy hair growth. So, if you’ve lost weight because you’re eating less — intentionally or not — this might cause sudden hair loss.

The good news is that this type of hair loss is usually temporary. Once you start meeting your nutritional needs by eating a balanced diet, your hair will slowly start growing back.

Bariatric Surgery and Hair Loss

Major surgery — even when it’s lifesaving — can also cause hair loss.

One systematic review of research found that about 57 percent of people experienced hair loss after bariatric surgery.

For some people with obesity, bariatric surgery (AKA weight loss surgery) is necessary for losing weight and reducing the risk of certain health conditions.

Popular weight loss surgeries include gastric bypass and sleeve gastrectomy surgeries. These procedures work by making it impossible to eat a lot, thus resulting in weight loss.

Because you can’t eat that much, weight loss surgeries can lead to nutritional deficiencies, which can cause hair loss.

Beyond nutritional deficiencies, surgery itself can lead to hair loss. This is because surgery takes a toll on the body, possibly disrupting your hair growth cycle.

Illness and Hair Loss

Certain illnesses can cause hair loss. Being very sick can be a shock to the system, which leads to telogen effluvium.

And sometimes, the same illnesses that cause you to lose weight can also cause you to lose hair strands. So, if you’ve lost weight after a recent bout of sickness, you might also notice some hair loss.

Illnesses that trigger hair loss can include infections as well as high-fever illnesses, like flu.

Will Hair Loss From Weight Loss Grow Back?

Usually, yes. Hair loss from weight loss is typically telogen effluvium, which is usually temporary.

Remember that hair growth takes time. With telogen effluvium, you’ll usually notice hair loss several months after you encounter the stressor. It may take a while to address the issue, after which your hair should start growing again.

Word of warning, here: while weight loss-related hair loss may grow back, other types of hair loss can be permanent.

Remember, there are several causes of hair loss. Just because you noticed hair loss around the same time you lost weight doesn’t mean the two are related.

If you’ve noticed the signs of balding, it’s important to get an expert opinion because it may be male pattern baldness, also known as androgenetic alopecia. This is the most common cause of male hair loss — far more common than weight loss-related hair loss.

It typically shows up as a receding hairline or thinning hair on the crown of your head, and gets worse over time. Unless, of course, you treat it early. So, if you’re not keen to rock a bald head, you’ll need to start treatment ASAP.

How to Prevent and Treat Hair Loss From Weight Loss

If you’re on a weight loss journey, it’s important to look out for your hair and overall wellness — and not just your waistline!

To prevent hair loss from weight loss, try the following:

• Eat a healthy, balanced diet. Even if you’re reducing your calorie intake, try to eat a variety of nutrient-rich foods on a daily basis.

• Get enough protein. Adequate protein intake is essential for hair health and your general well-being. Protein can help you feel fuller for longer, too, which is great for sustainable weight loss.

• If you have bariatric surgery, stick to doctor’s orders. Stick to your dietitian or surgeon-created eating plan — it’ll help you meet your nutritional needs.

• Try supplements. If you have a nutritional deficiency, supplements can help. Our biotin gummies, for example, contain a range of essential nutrients for hair health.

If you’ve noticed hair loss after losing weight, you can also try minoxidil.

This FDA-approved topical treatment is available over the counter in the form of foam or liquid solution. Minoxidil stimulates hair growth by boosting circulation in the scalp and shifting your hair follicles into the anagen phase.

If you’re experiencing hair loss because of something else, though, other hair loss treatments like finasteride might be more effective.

Weight Loss and Hair Loss: The Final Word

So, can weight loss cause hair loss? Yes, sometimes it can — especially if you quickly lose a lot of weight.

Here’s what you need to know about hair loss after weight loss:

• Rapid weight loss may cause telogen effluvium. Although shedding a few pounds won’t make you bald, severe and fast weight loss can result in hair shedding.

• There are many reasons why this happens. Crash diets can cause nutrient deficiencies, which can cause hair loss. Bariatric surgery can also cause hair loss. Certain illnesses may cause you to lose both weight and hair.

• It’s usually temporary. New hairs will grow once you address the underlying issue — whether it’s an iron deficiency or an illness. Plus, certain treatments can help promote hair regrowth.

Check out these tips for making hair grow faster if you’re trying to speed up the growth process.

If you’re not sure whether you’re experiencing temporary hair shedding or another type of hair loss, it’s a good idea to get medical advice.

Hims can help you book an online consultation with a healthcare provider. They can help assess the cause of your hair loss and suggest possible treatment options. Get started on your hair loss treatment journey today!