If you’re receiving treatment for obesity, you may discover side effects you didn’t expect, including itchiness. “My face has been turning red and very itchy. According to my pharmacist, it could be one of my meds,” one MyObesityTeam member said. Another replied, “I’m so itchy I want to rip my skin off.”

Although itchy skin isn’t a very common side effect of weight loss treatment, it is possible. Here are the most common reasons obesity treatments may cause itching, and when to talk to your doctor.

Potential Causes of Itchy Skin With Weight Loss Treatment

If you have itchy skin (also called pruritus) that started around the same time as weight loss or starting a new obesity treatment, it’s reasonable to suspect they may be related. Some of the most common minor causes of itchy skin include skin dryness (xerosis), scars (including stretch marks), psychiatric reasons — such as anxiety, obsessive-compulsive disorder, or depression — and irritation or allergic reactions. All of these might be related to weight loss or a new treatment.

Other potential links between obesity treatment and itchy skin could include:

• Itching as a side effect of a GLP-1 drug
• Skin changes related to diet or restricted eating
• Side effects from bariatric surgery (weight loss) due to not absorbing nutrients properly
• Dry skin caused by dehydration related to GLP-1 drugs
• Irritation caused by loose or excess skin

GLP-1 Drugs and Itchy Skin

GLP-1 drugs, also called glucagon-like peptide 1 receptor agonists, are commonly used to treat obesity and type 2 diabetes. These medications help with weight loss by slowing stomach emptying and increasing feelings of fullness after eating. Some studies suggest that side effects of GLP-1 drugs can include rashes and skin irritation. These medications began to be used widely as an obesity treatment only recently, so more studies and investigation are needed to fully understand the possible side effects and long-term impacts of their use.

Documented skin-related common side effects from GLP-1 drugs include itching and reactions at the injection site, hypersensitivity of the skin, rashes, and immune-related skin responses.

Immune Response Reactions

In some cases, GLP-1 drugs may worsen existing inflammatory skin conditions, such as psoriasis and hidradenitis suppurativa (HS). In other cases, research suggests GLP-1 drugs may actually reduce inflammation and improve certain immune-related conditions, including lupus. If your GLP-1 side effects are severe or dangerous, your doctor may recommend that you stop taking them.

Injection Site Irritation

The most common skin issue associated with GLP-1 drugs is injection site irritation. This usually appears as localized redness or discoloration, itching, and minor swelling. This reaction is usually minor and will go away on its own, but it can sometimes be chronic or cause long-term damage.

If injection site symptoms don’t improve or if they become painful, it’s important to let your doctor know.

Dehydration and Dry Skin

In addition to reducing hunger, GLP-1 drugs can also suppress your feelings of thirst. As a result, some people drink less water than their bodies need. If you think you might not be drinking enough water, it’s a good idea to track your hydration. Aim for about 2 liters of water a day. This includes fluid from all sources. Being dehydrated is harmful to your skin and can cause dryness. Dry skin is one of the leading causes of itchiness. Drinking more water could help soothe your skin and has many other health benefits as well.

Increasing your water intake, using gentle over-the-counter moisturizers, and avoiding long or hot showers may help your skin feel better. If itching improves when you drink water and moisturize, dryness may be the main cause.

Damaged Skin Barrier

Dry skin caused by dehydration can also make existing skin conditions feel worse. When your skin doesn’t have enough moisture, its protective barrier can weaken, making it more sensitive to friction, temperature, and irritants like soap or clothing. Making skin care changes like using fragrance-free cleansers, applying moisturizer after bathing, and using a humidifier to keep indoor air from becoming too dry may help reduce irritation while your body adjusts to treatment.

Diet and Rashes

Rapid changes in diet can also affect the skin. Very low calorie intake or highly restrictive eating patterns may increase the risk of nutrient deficiencies that can harm your skin.

Being low in certain vitamins and minerals can cause rashes, dry skin, eczema, flaky skin, and a damaged skin barrier function. Certain crash diets are also linked to rashes. For example, the keto diet, a low-carb diet, has been associated with an itchy rash called the keto rash. This rash is uncommon but may occur during periods of strict carbohydrate restriction.

Itching After Bariatric Surgery

Itchy skin can also happen as a side effect of bariatric surgery for weight loss. In these surgeries, the stomach is cut or reduced in size, leading to a significantly decreased ability to eat.

In many people, bariatric surgery can reduce body weight by 30 percent to 40 percent. Dramatic weight loss changes your body a lot and can impact the skin in different ways, including a deficiency of certain vitamins due to decreased nutrient absorption. In some cases, keto rashes (itchy rashes caused by strict dieting) have also been associated with bariatric surgery.

Loose Skin and Irritation in Skin Folds

Loose or excess skin that remains after you lose a lot of weight can create discomfort, odor, or itching in skin folds. Also called intertrigo, this irritation can be caused by bacteria or Candida (yeast), creating a fungal infection. It often happens when skin rubs together or traps moisture.

One study reported that up to 90 percent of people who’ve had weight loss surgery deal with the negative effects of excess skin. Although rare, it is also possible for a serious infection to develop in skin folds.

Members Share Tips on Skin Care

MyObesityTeam members have shared their experiences with itching. One member said, “I haven’t been feeling too good. I got this rash under my arm, and everything the doctor gave me isn’t working. Now it’s spread to my left breast, and all it does is itch. The doctor says it’s yeast.”

Another said, “I have a rash under my belly roll. It is uncomfortable and makes me feel horrible.” Another member came in with reassurance and tips on what’s worked for them. “It’s very common. Get some good salve, and once you get it cleared up, put some powder on the area to dry it out.”

Talk to Your Doctor

If you experience widespread rash, hives, swelling, or trouble breathing, contact your doctor right away. You should also reach out to your care team if you experience itching or skin discomfort that lasts for more than two weeks, or if your symptoms are interfering with your sleep or ability to complete daily tasks.

Obesity can cause or worsen some skin conditions, and it’s also true that itchy skin could be caused by a treatment you’re getting for your obesity. Don’t hesitate to talk to a healthcare professional if you’re worried about your symptoms.

Join the Conversation

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What has helped you with itchy skin from obesity treatment? Let others know in the comments below.