GLP-1s, and the questions we should be asking

Working in the space of health behaviour change, I get a lot of questions about my views on weight loss medication (GLP-1s, or “weight loss jabs”). 

Often this conversation can feel quite polarised. I think this is because we struggle to hold two things at once: these medications can genuinely help people, and there are still important questions we need to ask.

GLP-1s are genuinely transformative for many people

There’s no denying that these medications can have a positive effect on weight loss: evidence shows that on average, people lose up to 16% of their body weight while taking them. We’ve also seen this evidence with our own eyes - it feels like we now all know at least one person who has taken the medication, and their size has dropped dramatically. 

And the results aren’t just physical: people often report that being on the medication massively reduces their “food noise” (constantly feeling preoccupied with thoughts of food). For many, this is a huge game-changer - even more so than the weight loss.

But the actual picture is a bit more complex

The challenge with emerging treatments like this is that the strongest evidence we have comes from the organisations with the greatest incentive to demonstrate benefit. This means that there’s a risk of bias - because they have a vested interest in the drug being successful. Often this bias is unconscious - the funders and researchers aren’t actively trying to fudge the results, but they might unintentionally make choices which skew the findings.

Furthermore, some have raised questions about whether the evidence is reported fairly, and about the long-term safety of the medication (particularly at the higher doses required for weight loss). 

Additionally, the side effects are not insignificant. The majority of people experience gastrointestinal discomfort such as nausea, vomiting, and diarrhoea (which can in some cases lead to severe dehydration). There are also other more serious risks, including pancreatitis, gastroparesis, significant muscle loss, and malnutrition. 

This doesn’t mean that the evidence is “wrong” or that the medication is unsafe - but it is an important reminder that these medications aren’t just a “commercial diet aid”: they are a serious, regulated medication. We should be looking at the evidence critically, and always be using the medication under the guidance of a clinician.

A lifelong medication?

Another pertinent question is how long people should expect to be on these medications. 

We know the body responds to weight loss with biological adaptations that make maintenance difficult. GLP-1s appear to be no different in this respect: when the medication is stopped, appetite regulation often changes again and weight regain is common - and really fast.

Some people are therefore often talking about them being a life-long medication - like statins, or blood pressure meds. I have two concerns with this:

1. Do people want to be taking this medication for the rest of their lives? Some might - some might not want to (or can’t afford to).

2. We don’t yet have good evidence on the impact of taking this medication for many years. It might be safe and totally fine, but it might not - and we just don’t know yet.

We know that when our weight “cycles” up and down, this can be really bad for our health - and taking then stopping a GLP-1 could contribute to this. Given the impact that dieting has on our metabolism, it’s quite possible that GLP-1s will lead to similar changes. People considering these drugs need to therefore consider whether they’re open to staying on it for the rest of their lives - and how it might impact their relationship with food in the long-term.

So what should we make of GLP-1s?

I think the biggest mistake we can make is treating GLP-1s as either a miracle solution or something to be dismissed entirely.

The evidence is clear that these medications can be genuinely life-changing for many people. They have challenged the idea that weight has always been about willpower, and hopefully they will move us towards a kinder understanding of the complex biology behind body weight.

But they are also not a simple solution to a complex problem. We still have important questions about long-term use, access, weight regain, and what happens when people stop taking them.

If you're considering taking a GLP-1, I don't think the question is simply "do they work?" - because for many people, they clearly do (at least in the short-term). The more useful questions are:

• is this the right choice for me?

• What problem am I trying to solve here, and is the medication going to actually help with that?

• How would I feel if I need to stay on it for life?

• Do I understand both the benefits and the uncertainties?

• And what support do I need alongside medication to help me look after my health in the long term?

Because ultimately, medication can be a powerful tool - but it is still just one part of the bigger picture.