Does Wegovy make you tired? Here's why it might be happening

So, you've recently started taking Wegovy, and you're feeling excited for the next phase of your weight loss journey.

Maybe you've even started to see some promising results on the scale, or in how your clothes fit. You're full of motivation until suddenly, it hits you. You're exhausted.  

Maybe you're waking up in the morning feeling weary, despite getting 8 hours of rest. Or, perhaps, you get sluggish every day after work like clockwork, and all you can do is doom scroll on your phone.

Either way, you're wondering why you felt fantastic a week ago, and undeniably 'blah' now.

Dealing with fatigue as a side effect of Wegovy can be frustrating, especially if it prevents you from sticking to your daily movement habits. The good news is, while it's common, it's also something that can be easily prevented with the right steps.

Read on to learn more about why Wegovy could be making you tired, and how you can curb the effects to feel energised every day.

Why does Wegovy make you tired?

You're not imagining it — weight loss medications (including Saxenda and Mounjaro) have been reported to make some people more tired than usual.

In fact, in clinical trials, fatigue was one of the most common side effects of Wegovy [1]. It's not currently known exactly how (or why) Wegovy and other weight loss medications cause tiredness.

However, some speculate it's actually an indirect effect of the medication, rather than being related to the active ingredient, semaglutide, itself. There are a few different reasons this can happen:

Your reduced calorie intake can impact your energy levels

As a GLP-1 receptor medication, Wegovy works by simulating the glucagon-like peptide-1 hormones our bodies naturally produce, which are responsible for regulating appetite.

As well as keeping us full for longer, this helps switch off the hunger signals in our brains. The result? We eat considerably less. While reducing food intake obviously can help us lose weight, there is a flip side. At the end of the day, food is energy.

If you're not eating enough of it to fuel your lifestyle, there's a good chance you're going to feel wiped out.

Even if you're not experiencing the typical hunger signals like that gnawing feeling in your stomach or a rumbling stomach, fatigue can be your body's way of letting you know it's not getting adequate nourishment.

You may not be getting enough protein

If you find that you feel physically weak as well as tired, a lack of protein could be the culprit. When losing weight quickly (as can be the case on Wegovy) it's particularly important to eat sufficient amounts of high-quality protein in order to prevent muscle loss.

Research shows that as much as 40% of the weight loss seen on Wegovy and other weight loss medications can be lean muscle mass [2].

Not only can this negatively impact your metabolism (potentially leading to weight gain if you ever go off the medication), it can give you that weak, 'spaghetti arm' feeling.

Luckily, you can prevent this from happening. By prioritising protein in your diet, you can help preserve muscle mass while also giving yourself the fuel you need to get through the day.

Wegovy can impact your sleep

When we find ourselves feeling a bit drowsy during the day, our sleep schedule is one of the first things we should look at. How many hours of shuteye are you getting each night? Are those quality hours of sleep (including deep sleep?)

While there's currently no evidence directly linking Wegovy to poor sleep, it's worth noting that it interacts with the part of the brain responsible for the sleep/wake cycle [3].

Known as the body's 'internal clock,' our brains have a structure inside them called the hypothalamus.

As well as releasing hormones that tell us when it's time to wake or sleep, it's also responsible for regulating our appetite. This perhaps explains why you might find yourself alert, awake and staring at the ceiling if you go to bed hungry.

One study in rats found that Saxenda, another GLP medication with a similar effect to Wegovy, lowered wakefulness and altered the rat's sleep patterns [4].

While animal studies do not always generalise well to humans, this shows a potential link between weight loss medications, sleep, and energy levels.

Wegovy can lower blood sugar

One of the functions of GLP-1 receptor agonists inside the body is to regulate blood sugar. For many people — especially those are who insulin resistant — this is a positive thing that can actually assist with weight loss as well as stabilising your energy levels.

However, if your blood sugar is naturally on the lower side, it could result in adverse effects [5]. If you notice any other symptoms like dizziness or lightheadedness, it's important to consult with a healthcare professional.

How long can Wegovy fatigue last?

You're most likely to feel tired when you're on a higher dose of Wegovy, especially if your body is still getting used to it. This is why it's so important to gradually increase your dose as instructed, so you can build up a tolerance.

While there's no hard and fast rule about how long you can expect to experience side effects (as well as other common side effects like an upset stomach and mild abdominal pain), it's important to chat to your doctor if symptoms persist for more than a few weeks.

Tips for dealing with Wegovy fatigue

Ready to get back to feeling like yourself again? Here are some of the practical steps you can take to minimise tiredness while taking Wegovy:

Prioritise your sleep

When you're feeling tired, it can be tempting to reach for coffee or English breakfast as an instant pick-me-up. While there's nothing wrong with enjoying a cuppa as part of your daily routine, using it as a bandaid solution can actually backfire.

If you consume too much caffeine or have it too close to bed, it can disrupt your circadian rhythm — and so the cycle continues, where you get yet another poor night's sleep.

Try to have your last coffee at least 6 hours before hitting the hay, as well as implementing other sleep hygiene practices like limiting screen time before bed.

Avoid drinking alcohol

While semaglutide doesn't have any known drug interactions with alcohol, both substances have been found to lower your blood sugar levels.

In alcohol's case, this happens after an initial spike in blood sugar — talk about a rollercoaster! So, if you're already experiencing side effects like fatigue, booze may exacerbate this [6].

Plus, alcohol is a depressant, so it's likely to only contribute to the feelings of drowsiness (especially if you're hungover the next day!)

It's important to note that for those with type 2 diabetes, excessive drinking can have serious side effects — as it can cause your body to go into a state of hypoglycemia (low blood sugar). So, be sure to take extra care when enjoying a tipple, if you fall into this category.

Stay hydrated

Often, that drowsy, 'brain fog' feeling is actually a sign we're dehydrated! It's extremely important to keep your fluids up, especially if you're experiencing Wegovy side effects like diarrhoea.

By getting in plenty of h2O, you'll not only help prevent fatigue, but it will also help flush out any water weight — which can lead to faster results on the scale.

Nourish your body

It's almost inevitable that when you start Wegovy treatment, you will eat fewer calories by eating smaller meals (and in some cases, less frequent meals.)

However, this doesn't mean that you should attempt to eat as little as possible. While taking Wegovy or other weight loss medications, it's important to ensure you're not in too extreme of a calorie deficit.

Losing the weight slowly but surely is the best way to ensure it's sustainable, and that you feel great while doing so.

Just as important as how much you're eating is what you're eating. Make sure you're getting in plenty of foods rich in vitamins and minerals, to ensure you don't develop any nutrient deficiencies.

For example, iron deficiency (otherwise known as anaemia) is a common cause of fatigue, so it's crucial to make sure you're getting enough through meat, eggs, fortified cereals, or plant-based sources like leafy green vegetables.

The good news is, you don't have to figure out what to eat (and when) on your own.

With our Weight Reset Programme, we combine weight loss medications like Wegovy with ongoing support from health coaches and dietitians, so you always know exactly what to put on your plate to fuel your body.

Our weight loss experts work with you to create a dietary plan that works for you — so you enjoy everything you're eating and feel amazing. You'll have all the tools you need to lose weight and keep it off for good.

To take your next step in your weight management journey, check your eligibility here.

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