
The moment when you’re approved for GLP-1 therapy is so exciting – but also probably a bit scary as you’re stepping into the unknown. Self injection – and all those awful stories about side effects that you’ve seen on YouTube!
Not to worry. Here is a quick primer on what to expect on your starting dose. Everyone who is prescribed Mounjaro (currently, the most commonly prescribed therapy) will start on a low dose of 2.5mg. It is usually well tolerated and the side effects are usually mild!
NOTE: Although these therapies have a strong safety profile, as with any therapy, there is always a risk that you might have an adverse reaction. If there is any effect or change that you are concerned about, then give your doctor a call! There’s no point taking any chances with your health.
The key side effects to be aware of at this starting dose are:
- Dry mouth
- Nausea
- Constipation
- Reflux
- Fatigue and feeling dizzy for a few moments if you get up too quickly
There are more possible side effects, of course, and these are included at the end.
CAVEAT: If you are 3 stone (~40lb, ~20kg) or more overweight, you might find that you dont feel very different to normal on the starting dose. This is likely for two reasons: first, the drug is more ‘spread out’ across your body, so the dose in your bloodstream is lower than if you had a lower bodymass. Second is that being more overweight can mean that you are less sensitive to the therapy, and so need to take a higher dose to feel an effect.
Let’s take each of the main side effects in turn.
Dry mouth
Within a few hours of your injection, you might notice a dry mouth. This is a common side effect among my clients – with some experiencing it more severely than others. It usually eases after a few weeks. Some don’t get this at all.

Solution! Sipping water regularly. This helps you to stay hydrated [which is a noted issue with some people who are on GLP1s].
Nausea
If you bear in mind that GLP-1 therapies mimic the body’s natural satiety signal – the signal that we’ve eaten a meal – then the well publicised side effect of nausea makes sense.
Most of us know the sensation of “I’ve had enough now” at the end of a main course in a restaurant. If we then decide to order sticky toffee pudding from the dessert menu, we might feel a bit of nausea after eating it as we’ve gone beyond our feeling of fullness [‘satiety’].
Being on GLP1 therapy means that sense of satiety is present most of the time, and even when you feel hungry, usually you will not have to eat much to feel satiated again.
Solution!
*eat your meals slowly, pay attention to how you’re feeling and stop as soon as you feel satiated.
* Choose an injection site that is not the stomach area, as anecdotally, injections in this area can make feelings of nausea more likely.
Constipation

Another well known effect of GLP1 therapies is slower stomach emptying after a meal and slower transit of meals through the digestive system, and this often leads to constipation.
Solutions
- Make what you eat count: fibre, fibre and more fibre [non-starchy veg, lentils, fruit, nuts and seeds [as well as protein and fat, of course – see the recipe section for ideas].
- If the problem persists, consider gentle, natural laxatives like psyllium husk.
Reflux

As I mentioned in the last point, GLP1s slow stomach emptying, which means that your evening meal might not be fully digested by the time you go to bed and you can get reflux.
Solutions!
- Eat your evening meal earlier – ideally three to four hours before bedtime.
- Eat light, easy to digest meals of vegetables, meat or fish, and perhaps some fruit [if tolerated],
Fatigue
The last main effect of GLP1 therapies is that they lower your blood sugar – which is why they’re so useful for diabetics [only approved for type 2 at the moment, though]. You will also probably be eating very little – which, combined with the blood-sugar lowering effects of GLP1s means you can feel really tired – and sometimes a bit dizzy if you get up too quickly.
Solution!
- Eat a small amount of carbohydrate-based food, such as a banana, half a slice of bread and cheese, butter or jam, small piece of date bar. My clients – and I – have found this works.
The take home…
Because of the way that GPL1 therapies work, there are bound to be some side effects. These are usually fairly mild. If you experience severe side effects – or even mild ones that worry you, PLEASE speak to either your prescriber or your doctor.
I happily offer lots of free information, including my own real-life experiences taking GLP1s and the experiences of my clients.
I also offer a 10 minute free call where I can answer any major questions that you have. I am passionate about these therapies – like many others, I have personally found them to be life changing.
This might be enough, but if you would like something more individual and personalized, then I offer one-to-one coaching, in person or via Zoom.
I can help with:
- How to get approved for therapy at one of the countless online pharmacies
- How to optimise diet and nutrition during your weight loss journey
- Supplementation – so important (not all supplementation is ‘expensive pee’!)
- Personalised and pragmatic guidance for maintaining strength and muscle mass
- Applying the latest science for optimal nutrition and lifestyle for the best change of a long and healthy life
If this sounds like something you would be interested in, feel free to contact me at: glp1coach@gmail.com