Do Antihistamines Cause Weight Gain?

Do Antihistamines Cause Weight Gain?

Have you ever taken an allergy pill and then felt extra hungry or tired afterward? Some people believe that antihistamines, the medicines we use to treat allergies like hay fever or itchy skin, might be linked to weight gain.

These medicines help stop sneezing, runny noses, and itchy eyes by blocking a chemical in your body called histamine. But what many people don’t realise is that histamine also affects your appetite and how your body uses energy. When you take a medicine that blocks histamine, it may increase your appetite or cause your body to function slightly more slowly.

In this blog, we’ll look at what scientists say about antihistamines and weight gain. We’ll talk about how these medicines work, which ones might affect your weight more than others, and what you can do if you're worried. Let’s get started!

What Are Antihistamines?

To understand how antihistamines might contribute to weight gain, it is helpful to know how they work in the body.

Your body makes a natural chemical called histamine. Histamine has many jobs. It helps you stay awake, aids in stomach digestion, and triggers allergy symptoms such as sneezing and itching. When you breathe in something you are allergic to, like pollen or dust, your body releases histamine. This is what causes you to sneeze, have a runny nose, or get itchy eyes.

Antihistamines are medicines that block histamine. They are used to treat conditions such as hay fever, skin rashes, and insect bites. By blocking histamine, antihistamines stop the allergy symptoms. However, they can also block the other functions histamine performs in your body, such as helping to regulate your appetite and energy levels.

There are two main kinds of antihistamines:

First-generation antihistamines

These are the older ones. They include medicines like:

• Diphenhydramine (often called Benadryl)
  
  
• Chlorpheniramine
  
  
• Hydroxyzine

These medicines can cause drowsiness because they can cross the blood-brain barrier. They might also make you feel hungrier than usual.

Second-generation antihistamines

These are the newer types. Some examples are:

• Cetirizine (known as Zyrtec)
  
  
• Loratadine (known as Claritin)
• 
  Fexofenadine (known as Allegra)

These usually do not make you tired because they do not penetrate the brain as deeply. But some people still feel a bit hungrier when taking them.

So, antihistamines help with allergies, but they may also cause you to eat more or feel more tired. This could lead to gaining weight over time.

Antihistamines and Weight Gain: How do they Work?

Although the connection between antihistamine use and weight gain is not entirely clear, research suggests that there may be one. Both children and adults have experienced this. Additionally, understanding the role of histamine in the body may help us comprehend how antihistamines can cause weight gain.

Many physiological functions are carried out by histamine in the body. When pollen counts are high, allergy sufferers experience runny noses, itching, and sneezing due to their role in triggering allergic reactions. In humans, histamine may also control appetite and metabolism. The release of histamine has been shown to cause a reduction in food intake in response to its release, suggesting that it can help us feel full or signal that we should stop eating in response to its release. Taking antihistamines may block this effect, leading to an increase in food intake and a higher risk of weight gain.

There is also a sedative effect associated with antihistamines. It can be helpful when you need to fall asleep, but not when exercising. In addition to fatigue leading to decreased physical activity, the use of antihistamines could also contribute to increased body weight. More research is needed to understand how antihistamines can affect weight and the underlying causes.

How Might Antihistamines Cause Weight Gain?

There are a few reasons why taking antihistamines might make someone gain weight. Even though scientists are still studying it, here are some ideas that could explain it:

• They can make you feel hungrier: Histamine helps your brain know when you are full after eating. When antihistamines block histamine, your brain might not get that “I’m full” message. That means you might keep eating, even when your body has had enough.
  
  
• They can cause drowsiness: Some antihistamines, especially older ones like Benadryl, can cause drowsiness. If you feel sleepy, you may move around less or skip exercise. When you are not active, your body burns fewer calories.
  
  
• They might slow down your body’s engine (metabolism): Your metabolism is how your body turns food into energy. If antihistamines slow this down, your body might store more fat instead of burning it for energy. This could lead to weight gain over time.
  
  
• Some antihistamines are stronger than others: Some medicines, like one called ketotifen, are known to increase appetite and cause weight gain. Doctors sometimes use it to help people who need to put on weight. This shows that some antihistamines affect the body more than others.
  
  

In simple words

Antihistamines might make you want to eat more, move less, and store more fat. This is why some people believe they can cause weight gain, especially if you take them often or for a long time.

Antihistamines and Weight Gain: What Can You Do?

You should consult your healthcare provider if you have gained weight due to antihistamines or are worried about this side effect. Your doctor may be able to offer you a less weight-gaining treatment option.

Medication-induced weight gain can also be countered by implementing multiple weight management strategies.

• Diets that contain fewer calories and are healthy are the most effective and healthy means to lose weight. This is achieved by consuming a diet rich in fruits, vegetables, lean proteins, whole grains, and healthy fats. A Registered Dietitian can help you with this if you need assistance.
  
  
• Physical activity plays a vital role in weight management. Physical activity burns calories. Trying short bursts of increased activity is a good idea if you do not enjoy exercising or are having difficulty fitting it into your busy schedule. For example, taking your dog for a walk a few times a day is a great way to exercise while watching your favourite TV show or using a stationary bike.
  
  
• Self-monitoring - Studies have shown that keeping track of your calorie consumption, physical activity, and weight is beneficial for weight loss. To maintain a healthy weight, it is helpful to keep a journal or use a more tech-savvy tool, such as an app.
  
  
• Get sufficient sleep - Sleep deprivation is known to contribute to weight gain. Allergy symptoms can worsen the effects of poor sleep on sleep quality. Get at least 7 hours of sleep each night by going to bed around the same time. Let your healthcare provider know you want to avoid weight-promoting medications if allergy symptoms wake you up at night.
  
  
• A healthcare provider may be able to help you if you're having trouble losing weight or gaining weight despite implementing several healthy habits. Weight management can be complex for several reasons, including the side effects of medication. A healthcare provider can make appropriate recommendations to determine if a medication is contributing to a medical problem. Additionally, they can implement weight loss medications if necessary, as well as nutrition and activity habits based on research.
  
  

What Happens If You Stop Taking Antihistamines?

Some people say they start to lose weight after they stop using antihistamines. This could be because they feel less hungry or have more energy when they are no longer taking the medicine.

If antihistamines were making you tired or extra hungry, stopping them might help you feel better. You may want to eat less and move more, which can aid in weight loss over time.

But you should never stop taking medicine on your own. Always speak to your doctor first. If you stop taking your medication suddenly, your allergy symptoms may return and worsen.

Your doctor can help you choose a more suitable medication if weight gain is a concern. There are other allergy treatments, such as nose sprays or allergy injections, that may not affect your weight.

Frequently Asked Questions

Can antihistamines make you gain weight quickly?

Most people do not gain weight quickly from antihistamines, but some notice a slow increase over time, especially if they take them every day. This may happen because the medicine makes you feel hungrier or more tired, which can lead to increased eating and decreased physical activity.

Which antihistamines are least likely to cause weight gain?

Second-generation antihistamines like loratadine (Claritin) and fexofenadine (Allegra) are less likely to cause weight gain because they usually do not make you sleepy or increase your appetite. These are often better choices if you are worried about antihistamines and body weight changes.

Can stopping antihistamines help with weight loss?

Some people notice that they lose a bit of weight after they stop taking antihistamines. This could be because they feel less hungry or more active. However, it is essential to consult your doctor before discontinuing any allergy medication.

Why do antihistamines make some people feel hungrier?

Antihistamines block histamine, which helps control hunger signals in your brain. When histamine is blocked, your brain might not know when you are full, so you may keep eating. This is why some people experience increased appetite from antihistamines.

Are allergy medicines that cause weight gain safe for long-term use?

Many antihistamines are safe for long-term use, but if they are making you gain weight, it is a good idea to speak with your doctor. You may be able to switch to a weight-neutral antihistamine or explore alternative methods to manage your allergies without risking weight gain.

Is weight gain from antihistamines permanent?

Weight gain associated with antihistamines is typically mild and can often be reversed by discontinuing the medication or making lifestyle adjustments. It is not usually permanent, especially if you stay active and eat healthy while taking allergy medication.

Do all antihistamines cause the same side effects?

No, not all antihistamines cause the same side effects. Older antihistamines, such as diphenhydramine (Benadryl), are more likely to cause drowsiness and increased appetite. In contrast, newer antihistamines, such as cetirizine or loratadine, are less likely to have these effects, which can impact weight differently.

How Can Weightloss Coach Help You With Weight Gain From Antihistamines?

Weight gain and difficulty losing weight may be caused or made worse by many medications. As an example, antihistamines are available. A Weight Loss Coach’s weight loss doctors conduct a thorough assessment, which includes reviewing your medications to determine if they could impact your weight. If more weight-friendly options are available, they can help you and your healthcare providers find them.