What to Know About Beta Blockers and Weight Gain 

It is perhaps inevitable that we all, at some point in our lives, will need to take a prescribed medication to treat an illness or to manage symptoms that impact our quality of life. Yet as helpful as the medication might be, there’s always a chance that it can cause side effects that have to be taken into account. An example of a relatively common medication that is used to treat numerous conditions is the type of drugs called beta blockers, and weight gain is one of the side effects that many people have reported. 

What Are Beta Blockers?      

Beta blockers are a class of medications that are normally used to treat conditions associated with the heart and circulatory system. Most of the time, beta blockers are prescribed to manage abnormal heart rhythms, but they are also used to prevent a second heart attack in patients who have already had an initial heart attack. Because of their slowing effect on the heart, beta blockers were also previously prescribed for patients with high blood pressure; in recent years, however, they have fallen out of favor as a first line hypertension treatment.  

How Do Beta Blockers Work? 

Many of the cells in our body have adrenergic receptors on their outer surface that are responsive to neurotransmitters released by the central nervous system. When a neurotransmitter is present, it binds to these cell receptors and the cells begin to change some of the ways they function. This is how, for example, the brain can initiate physiological changes around the body like the heart beating faster, airways in the lungs becoming more relaxed, and blood vessels constricting. These are all normal responses that can nevertheless be counterproductive in some circumstances. 

It is in these other circumstances when beta blockers may be prescribed. In fact, they are technically referred to as beta adrenergic receptor antagonists because of their core function as competitive antagonists. This means that they work by blocking the hormone receptors on some cells in order to prevent or dampen the normal physiological response. So rather than a neurotransmitter causing the heart to beat faster, for instance, the receptor is blocked and it will beat slower instead. Medication that can do this is helpful for a variety of medical conditions, including:  

• irregular heartbeat (arrhythmia)
• chest pain (angina)
• chronic heart failure 
• heart palpitations 
• hypertrophic cardiomyopathy
• some kinds of tremors
• migraine headaches
• high blood pressure 
• anxiety 
• glaucoma    

What Are the Side Effects of Beta Blockers?

Beta blockers are very useful for a wide range of conditions, and they can sometimes be beneficial for multiple problems at once. They’ve also been studied extensively over the past several decades and are a relatively inexpensive way to treat numerous medical problems. Yet because of how they impact the heart and circulatory system, they can also have non-trivial side effects: 

• heart rate that is too slow (bradycardia)
• low blood pressure (hypotension) 
• fatigue or drowsiness
• insomnia 
• feeling dizzy or lightheaded 
• headaches
• constipation or diarrhea 
• nausea 
• mild depression 
• lowered sex drive

The dosing of beta blockers can also have a significant effect on whether or not there are side effects and how intense they are. In general, the lower the dose, the lower the chance of having side effects that are noticeable or disruptive. Beta blockers can also have unpredictable interactions with other medications, and that’s why it can be a process of trial and error to find the right kind of medication at the appropriate dose for the condition in question. Sometimes switching to a different beta blocker can solve any issue of side effects. 

Do Beta Blockers Lead to Weight Gain? 

Another possible side effect of beta blockers is weight gain, though research has shown that the magnitude isn’t significant; the average amount of weight gained as a result of the medication is about 2.6 pounds. So even though any weight gain is generally unwelcome, it isn’t enough to contribute to obesity or substantially increase the likelihood of developing an obesity-related condition like heart disease or type 2 diabetes. There is also some evidence that a patient may experience minimal weight gain when first starting the medication before stabilizing after a few weeks.  

When weight gain does happen, it appears to be dependent on the type of beta blocker that has been prescribed. Research shows that newer beta blockers like carvedilol (Coreg) don’t lead to weight changes as a side effect at all. Older beta blockers, on the other hand, can potentially promote weight gain in some patients; examples include atenolol (Tenormin), metoprolol (Lopressor), propranolol (Inderal), and bisoprolol (Zebeta). These earlier generation beta blockers were once primarily prescribed for high blood pressure, but as noted earlier they aren’t used in that way any longer and are prescribed less frequently in general.   

How Does Beta Blocker Use Cause Weight Gain?

For the older generation of beta blockers that can lead to weight gain, the mechanism is not entirely understood. One possible explanation is related to fatigue, another known side effect of the medication. When patients feel tired and sluggish, they may be less likely to pursue exercise and other physical activity; this can lead to a calorie surplus (taking in more calories than are expended), which results in increased fat deposits. Some research has additionally shown a connection between beta blocker use and worsening insulin resistance; this means an increase in blood sugar levels and subsequent fat deposits.    

The truth is, though, that research into the effect of beta blockers on metabolism, glucose levels, and insulin resistance is still ongoing. As noted above, studies have shown an average weight gain of 2.6 pounds, but the fact that this stabilizes for many people after a few weeks suggests something other than a change in body composition. Indeed, one of the other possible explanations for weight gain is related to fluid retention. Patients on diuretics (medication that removes fluids from the body) are often directed to stop taking them when on beta blockers; this change can then lead to an increase in body fluid content that also increases body weight.    

Avoiding Weight Gain and Losing Weight

Depending on the condition that prompted beta blockers being prescribed as the preferred treatment option, some minor weight gain and other side effects may be inevitable. Fortunately, though, there are now more options available to treat conditions like hypertension. In fact, calcium channel blockers and angiotensin-converting enzyme inhibitors (usually referred to as ACE inhibitors) have become standard treatments for hypertension that are not known to cause weight gain. For some people, then, avoiding weight gain may be as simple as talking with their doctor about switching to a new medication.   

For most people, though, weight gain is a concern that can’t be explained by beta blockers. At True You Weight Loss, we understand that there are many complex factors involved in being overweight or obese. That’s why we are dedicated to offering a new approach that can bring about sustained, long-term weight loss. To learn more about True You’s highly effective non-surgical weight loss procedures, please contact us today to request a consultation. We want to help you find the freedom you’ve been looking for.