Semaglutide for weight loss?
Semaglutide is the new kid on the weight-loss block, but it’s looking promising (with some caveats!).
Most popularly by brand names Ozempic and Wegovy, it was first trialled to help diabetics*, and is now sought-after by the rest of the population too. So far, only Wegovy is FDA-approved for weight loss. It contains more semaglutide than Ozempic, and was developed specifically for weight loss, rather than for diabetes.
*Specifically: diabetics with type 2 diabetes. Because it works by helping the pancreas to make insulin, it’s of no help whatsoever to T1D folks, sadly. If you’re T1D and reading this though, today’s book of the day is for you!
First things first: does it work as marketed for diabetes?
It does! At a cost: a very common side effect is gastrointestinal problems—same as for tirzepatide, which (like semaglutide) is a GLP-1 agonist, meaning it works the same way. Here’s how they measure up:
- Head-to-head study: Effects of subcutaneous tirzepatide versus placebo or semaglutide on pancreatic islet function and insulin sensitivity in adults with type 2 diabetes
- Head-to-head systematic review: Semaglutide for the treatment of type 2 Diabetes Mellitus: A systematic review and network meta-analysis of safety and efficacy outcomes
As you can see, both of them work wonders for pancreatic function and insulin sensitivity!
And, both of them were quite unpleasant for around 20% of participants:
❝Tirzepatide, oral and SC semaglutide has a favourable efficacy in treating T2DM. Gastrointestinal adverse events were highly recorded in tirzepatide, oral and SC semaglutide groups.❞
What about for weight loss, if not diabetic?
It works just the same! With just the same likelihood of gastro-intestinal unpleasantries, though. There’s a very good study that was done with 1,961 overweight adults; here it is:
Once-Weekly Semaglutide in Adults with Overweight or Obesity
The most interesting things here are the positive results and the side effects:
❝The mean change in body weight from baseline to week 68 was −14.9% in the semaglutide group as compared with −2.4% with placebo, for an estimated treatment difference of −12.4 percentage points (95% confidence interval [CI], −13.4 to −11.5; P<0.001).❞
In other words: if you take this, you’re almost certainly going to get something like 6x better weight loss results than doing the same thing without it.
❝Nausea and diarrhea were the most common adverse events with semaglutide; they were typically transient and mild-to-moderate in severity and subsided with time. More participants in the semaglutide group than in the placebo group discontinued treatment owing to gastrointestinal events (59 [4.5%] vs. 5 [0.8%])❞
~ ibid.
In other words: you have about a 3% chance of having unpleasant enough side effects that you don’t want to continue treatment (contrast this with the 20%ish chance of unpleasant side effects of any extent)!
Any other downsides we should know about?
If you stop taking it, weight regain is likely. For example, a participant in one of the above-mentioned studies who lost 22% of her body weight with the drug’s help, says:
❝Now that I am no longer taking the drug, unfortunately, my weight is returning to what it used to be. It felt effortless losing weight while on the trial, but now it has gone back to feeling like a constant battle with food. I hope that, if the drug can be approved for people like me, my [doctor] will be able to prescribe the drug for me in the future.❞
~ Jan, a trial participant at UCLH
Is it injection-only, or is there an oral option?
An oral option exists, but (so far) is on the market only in the form of Rybelsus, another (slightly older) drug containing semaglutide, and it’s (so far) only FDA-approved for diabetes, not for weight loss. See:
A new era for oral peptides: SNAC and the development of oral semaglutide for the treatment of type 2 diabetes ← for the science
FDA approves first oral GLP-1 treatment for type 2 diabetes ← For the FDA statement
Where can I get these?
Availability and prescribing regulations vary by country (because the FDA’s authority stops at the US borders), but here is the website for each of them if you’d like to learn more / consider if they might help you:
