David Bridges
It’s laborious to go a day with out listening to one thing new in regards to the newest diabetes and weight problems drugs, semaglutide and tirzepatide. Normally, the excitement is optimistic, however there was a persistent declare made about these medication that will make any potential person cautious: They don’t solely show you how to shed extra pounds—they supposedly hole out your muscle mass on the identical time, making you weak and susceptible to all types of future well being issues down the road. However what does the present science say, and simply how fearful do you have to be about muscle loss if taking these medication?
Semaglutide (offered as Ozempic and Wegovy) and tirzepatide (offered as Mounjaro and Zepbound) are the most up-to-date additions to a category of medication often called incretins, which mimic hormones vital to our metabolism and sense of starvation, amongst different capabilities. Semaglutide mimics GLP-1, whereas the newer tirzepatide mimics GLP-1 and one other hormone, GIP. Each medication have been discovered to assist individuals safely, reliably, and considerably lose extra weight on common than food plan alone or different remedies, outdoors of bariatric surgical procedure. Research have additionally advised that these drugs can stave off coronary heart, kidney, and liver illness in overweight individuals susceptible to it and presumably even assist deal with habit and different circumstances not strictly tied to weight problems or diabetes.
As spectacular as these medication appear to be, no therapy comes with out its potential negatives. Customers will generally expertise gastrointestinal points like vomiting and diarrhea, although these signs are likely to wane over time. They could additionally trigger uncommon however doubtlessly critical problems like gastroparesis, sometimes called abdomen paralysis.
Some critics have additionally alleged that GLP-1s can dangerously sap our muscle mass, however specialists interviewed by Gizmodo say this declare isn’t at present backed by the information or our understanding of how these medication work.
The thin on muscle loss and GLP-1 use
For starters, the potential of muscle loss whereas taking these medication isn’t shocking. Lengthy earlier than Ozempic appeared on the scene, docs have recognized that this could occur with any type of weight reduction. Once we slim down, we usually lose some mixture of fats and fat-free mass, also referred to as lean physique mass, which may embrace our muscular tissues. And whereas there may be another elements of GLP-1s that assist us shed extra pounds, they primarily scale back our urge for food and improve our sense of fullness, main us to eat much less energy over time. In different phrases, there’s nothing significantly novel about how we shed extra pounds whereas taking them.
Research have discovered that when individuals lose vital weight by way of food plan alone or through bariatric surgical procedure, 20% to 30% of that weight is lean physique mass. And to this point, we’re not discovering that GLP-1 medication are veering dramatically from this baseline. A 2024 overview of medical trial knowledge on semaglutide, for example, discovered that the proportion of lean physique mass misplaced whereas losing a few pounds ranged from 0% to 40%. And enormous medical trials of tirzepatide have discovered that the share of lean physique mass misplaced is consistent with the share misplaced by way of food plan or surgical procedure.
“So it truly is on par,” Michael Weintraub, an endocrinologist and medical weight problems researcher at New York College Langone Well being, informed Gizmodo over the cellphone. “And there’s no motive to suppose there’s some distinctive mechanism of those GLP-1 agonists that’s inflicting a form of particular muscle mass loss.”
These numbers alone don’t inform the total image both. Even with the best figures, overweight individuals are nonetheless shedding extra fats than lean physique mass and that’s undeniably a internet optimistic, Weintraub says. One motive why muscle loss may be harmful is that it might probably make us frail and fewer in a position to perform our every day capabilities. However that’s completely not what the analysis is exhibiting. In comparison with placebo, individuals on these medication have reported a greater high quality of life and improved bodily functioning. Some restricted knowledge have additionally advised that these medication may cause a lack of lean physique mass however with out really compromising the standard of our muscular tissues.
“After I see my sufferers, they’ll say issues like: ‘Properly, I simply really feel so significantly better, I’m in a position to perform so significantly better. I’m in a position to go up and down the subway with out having to cease,’” Weintraub mentioned. “These are the outcomes, I feel, that truly matter.”
‘No knowledge to help the notion’
Samuel Klein is the director of the Middle for Human Vitamin at Washington College Faculty of Drugs in St. Louis. Earlier this month, he and different weight problems researchers wrote about this very subject for an article in JAMA and got here to the identical fundamental conclusion as above.
“We determined to overview the literature rigorously and truly discovered that there’s simply no knowledge to help the notion that weight reduction with GLP-1 agonist remedy causes results on muscle mass, or fats free mass, that result in abnormalities in bodily perform,” Klein informed Gizmodo over the cellphone.
There are some potential ways in which incretin medication might be riskier in the case of our muscular tissues. All the information talked about above pertains to people utilizing these drugs for both sort 2 diabetes or weight problems, however their success has additionally pushed a public demand that has often outmatched the accessible provide. That, mixed with excessive record costs (upwards of $1,000 a month) and low insurance coverage protection, has fueled a grey and black market for the medication, making it comparatively straightforward for anybody to get their palms on it, even when they don’t essentially want it. So somebody who’s already pretty skinny and is taking semaglutide may presumably grow to be underweight or lose related quantities of muscle, although Klein notes that he hasn’t seen any case reviews of this occurring but. Then once more, any drug’s dangers can outweigh the advantages when utilized by those who it’s not meant for.
Using muscle loss worries
The dearth of information supporting huge muscle loss hasn’t stopped some drug corporations from making an attempt to counteract the problem. A number of corporations are testing a mixture of GLP-1s with medication designed to achieve muscle or stop muscle loss. It’s definitely doable that these mixtures would possibly enhance individuals’s well being much more than taking a GLP-1 alone, particularly for older people who find themselves already at increased danger of shedding muscle as they age. However these trials shouldn’t be seen as an admission by Large Pharma that we actually have one thing to fret about both, Klein argues.
“It’s a therapy searching for an issue,” he mentioned. “I feel step one can be is to show that weight reduction with these drugs in a subset of individuals causes hurt by extreme muscle mass loss and decreased bodily perform. And till you show that, it’s unclear that stopping the muscle loss can have therapeutic results which might be price it.”
Actions to keep up muscle well being
If you’re nonetheless fearful about potential muscle loss from taking these medication or losing a few pounds one other method, then right here’s some encouraging information: We already know find out how to assist scale back or stop it.
“I spend lots of time within the clinic counseling sufferers on this, ensuring that they’re attaining ample protein consumption, after which ensuring that we’re spending effort on power, or resistance, coaching,” Weintraub mentioned. “As a result of we all know that [those two things] can actually mitigate the muscle mass loss that we’d see with anti-obesity drugs.”
For his or her half, specialists like Weintraub and Klein do endorse additional analysis trying extra carefully at muscle (and bone) loss whereas taking these medication. However they’re additionally unequivocal about the place the proof stands in the meanwhile.
“We simply should observe the information—it’s the yellow brick street—and never be wedded to any specific viewpoint. However proper now, there are not any knowledge that I’m conscious of supporting that this can be a downside,” Klein says.
Brandon Fletcher
