GLP-1 'weird' side effects: what TikTok gets right and wrong

What did @realdrbae actually say?

Dr. Jonathan Kaplan, who identifies as a GLP-1 expert and self-reported GLP-1 user, listed five "weird" effects he claims patients experience on GLP-1 receptor agonists. These include feeling cold all the time, food and beverage aversions (coffee and sweets specifically), acne improvement from eating less sugar, a new obsession with gourmand fragrances, and dealing with jealous friends. He closed by calling GLP-1s a drug class with "a really safe profile." That last claim deserves its own conversation.

To his credit, he flagged the perfume claim as anecdotal. He did not flag the others, and that's where things get complicated. Some of what he said has real science behind it. Some of it is a stretch. And one claim, that dermatologists are now prescribing GLP-1s specifically for acne, is moving faster than the evidence that's supposed to support it.

Does the science back this up?

Cold intolerance is real and documented, though the mechanism is still being sorted out. Food aversions also have solid biological grounding. The acne claim has some logic to it but leans on indirect evidence. The fragrance claim has no peer-reviewed support whatsoever.

On cold intolerance: rapid fat loss reduces the body's insulating layer and can lower metabolic heat production. A 2023 analysis published in Obesity Reviews (Müller et al.) noted that GLP-1 agonists can suppress thermogenesis alongside appetite, which may explain why patients report feeling cold. This isn't unique to GLP-1s. It happens with any significant caloric restriction. Calling it a GLP-1-specific effect is slightly misleading.

Food aversions, including to coffee and sweets, are pharmacologically plausible. GLP-1 receptors are expressed in reward-processing brain regions. Research by van Bloemendaal et al. (2014, Diabetes) showed GLP-1 receptor activation reduces dopaminergic responses to food cues. The coffee aversion specifically may also relate to slowed gastric emptying making caffeine feel more intense or unpleasant. This one checks out.

Acne improvement tied to reduced sugar intake has indirect support in dermatology literature. A 2012 randomized trial by Smith et al. in the American Journal of Clinical Nutrition found low-glycemic diets reduced acne lesion counts. But the claim that dermatologists are actively prescribing GLP-1s for acne is ahead of the clinical evidence, which remains observational at best.

What did they get wrong (or right)?

The food aversion and cold intolerance claims land reasonably well. The fragrance claim is TikTok folklore dressed up with a quick neuroscience guess about "a different dopamine source." That explanation is not supported by any published mechanism.

The acne claim is the most problematic. Saying "dermatologists offer GLP-1s now" implies this is an established practice. It is not. There are no FDA-approved indications for GLP-1 agonists in acne treatment. Some dermatologists may discuss it with patients who are already candidates for metabolic treatment, but prescribing semaglutide to clear skin is not standard of care and calling it "self-explanatory" glosses over that entirely.

The safety claim, "GLP-1s have a really safe profile," is also too breezy. These are powerful drugs with real risks, including pancreatitis, gallbladder disease, gastroparesis, and for liraglutide specifically, an FDA black box warning regarding thyroid C-cell tumors in rodents. Calling the profile "really safe" without any of that context does viewers a disservice, particularly at 1.4 million views.

What should you actually know?

GLP-1 receptor agonists are genuinely effective for weight management and blood sugar control in the populations they are approved for. They also carry a side effect profile that goes well beyond what this video covers, and some of those effects are serious enough that they should factor into any real conversation about starting these drugs.

The "weird" side effects in this video range from well-documented to completely anecdotal. Patients should expect nausea, vomiting, and gastrointestinal discomfort as the most common effects, none of which made this list. The cold intolerance and food aversion framing is useful patient information but incomplete without context about what drives those changes.

Anyone considering a GLP-1 agonist should have that conversation with a licensed provider who reviews their full health history, not a TikTok list, even one made by a surgeon who takes the drug himself. Self-prescribing does not equal expertise, and the fact that a doctor uses a drug personally does not make their anecdotal experience clinical evidence.