Trendy weight loss supplements — why they're popular and what the risks are, according to a doctor

• Trendy weight loss supplements have gone viral as alternatives to expensive prescription drugs.
• But herbs and supplements aren't proven to help you lose weight, a doctor said.

Next-generation medications such as semaglutide (sold as Wegovy and Ozempic) and tirzepatide (sold as Mounjaro) have made big headlines for impressive weight loss results as part of treatment from qualified obesity doctors.

However, shortages and the high cost of the medications have made them difficult to access for everyone who could benefit.

As a result, it may be tempting to try cheaper alternatives touted on social media or at the local health food store.

But while supplements are heavily marketed as weight loss solutions, research just doesn't back up the claims they work — and they can be dangerous, said Dr. Christopher McGowan, a board-certified physician in internal medicine, gastroenterology, and obesity medicine.

"As we know, patients are desperate for treatment and are looking for any and all options," he told Insider. "There isn't a single safe or effective proven herbal supplement for weight loss. You may end up just wasting your money."

In some cases, weight loss supplements can have health risks, since the industry is poorly regulated, making it difficult to know what you're getting, and how much.

Save your money by steering clear of misleading supplement claims, McGowan said.

If you're still tempted, protect yourself with some simple tips on making sense of popular products and labels.

The problem with berberine — aka "nature's Ozempic"

Berberine, a bitter-tasting substance found in plants like barberry and goldenseal, has been used in traditional medicine in China and India for centuries, but recently emerged as a massive weight loss trend in social media.

TikTok influencers say that the supplement has helped them shed pounds and balance their hormones or blood sugar, but these claims go far beyond what little research is available.

"It's been given the name "nature's Ozempic," unfortunately with no real basis in reality," McGowan said. "The problem is there's really no evidence suggesting it has any particular benefit to weight. The studies are very small, non-randomized, with a high risk of bias. If there is any benefit, it's not clinically significant."

Berberine can also have gastrointestinal side effects like nausea and it can interact with prescription medications, he added.

Be wary of proprietary blends that contain unknown ingredients

One popular type of weight loss supplements involves combining several different substances under one brand name, marketed with buzzwords like "metabolic health," "appetite control," or "fat shredding."

Known as "proprietary blends," these products can be particularly risky because the ingredients list is often difficult to understand and full of trademarked compounds that make it unclear what you're actually buying, according to McGowan.

"I would advise avoiding proprietary blends because there's no transparency," he said. "If you're going to take a supplement, stick with one ingredient. Avoid products with guarantees and big claims."

A major problem with supplements overall is that they aren't FDA-regulated, meaning there's little oversight into the ingredients and dosages beyond what companies say they contain.

"Manufacturers are entrusted to ensure safety of their own supplements," McGowan said.

As a result, they may not contain what's advertised, and could have a different dose than the label suggests. In some cases, supplements have even been found to contain dangerous contaminants, banned substances, or prescription medications.

Diet products like HCG and garcinia are trendy — but can be dangerous

Some trendy weight loss supplements have persisted for more than a decade, despite evidence that they're ineffective and may be unsafe.

HCG, short for human chorionic gonadotropin, is a hormone produced by the body during pregnancy. It was popularized in supplement form as part of a fast weight loss plan, along with a 500-calorie-per-day-diet, featured on "The Dr. Oz Show."

However, HCG is not approved for over-the-counter use and can have side effects including fatigue, irritability, fluid build-up and risk of blood clots.

"It's mind blowing to me that there are still clinics offering for weight loss when there's absolutely no evidence and there are warnings from the FDA and the American Medical Association," McGowan said.

Another weight loss treatment popularized by Dr. Oz is garcinia cambogia, a compound derived from the rind of a tropical fruit and said to prevent the body from storing fat. But studies found garcinia is no more effective for weight loss than a placebo. And other research has linked the supplement to liver failure.

Supplements like garcinia can seem attractive because of the misconception that natural compounds are inherently safer than medications, McGowan said, but plant-derived products still have risks.

"You have to remember that even if it's natural, the supplement is still manufactured in a factory," McGowan said.

Caffeine is used in many weight loss supplements, but it can be ineffective and risky in large doses

If you see products marketed as "fat-burners," odds are the main ingredient is just some form of caffeine, including green tea or coffee bean extract. Caffeine does have benefits such as increasing alertness but isn't a major factor in weight loss, according to McGowan.

"Basically it can boost energy, we know that, and while it may improve exercise capacity, it won't really move the scale," he said.

In large doses, caffeine can cause side effects like digestive distress, anxiety, and headache. Highly-concentrated caffeine supplements can also lead to dangerous overdoses potentially resulting in seizures, coma, or death.

Psyllium husk and other fiber supplements are healthy but not a weight loss solution

Another category of popular weight loss supplements focus on helping you get more fiber, a type of indigestible carbohydrate that helps support healthy digestion.

One of the trendiest fiber supplements is psyllium husk, a powder derived from the seeds of a plant native to South Asia.

While fiber is a crucial nutrient in a healthy diet, and can support weight loss by helping you feel more full after eating, there isn't strong evidence that it can help you shed pounds by itself, according to McGowan.

"There are no studies that fiber alone is going to cause significant weight loss," he said.

Eating more fiber, especially in the form of nutritious whole foods like vegetables, legumes, seeds, and fruit, is a good idea for overall health, though

5 herbal supplements touted for weight loss, with hard-to-believe claims

New versions of weight loss supplements are constantly emerging on the market, and old trends often resurface, making it hard to keep track of all the weight loss claims, McGowan said.

Other supplements that have been touted for weight loss but without evidence include:

• Aloe vera

• Calcium

• Chromium picolinate

• Guar gum

• Ephedra

Still, supplement companies continue to make bold claims, and it can be hard for a typical consumer to sift through the research.

"It's unfair to expect the average person to understand the claims — I can barely understand the claims," McGowan said. "You need to dig deep because products claim to have studies, but those studies may be poor quality and show nothing."

The bottom line is that there's currently no evidence to support any supplement as safe and effective for weight loss, he said.

"You can scan the supplement shelf and it's well-stocked with things that claim weight loss, but unfortunately they're not backed by the evidence," McGowan said. "I always recommend reaching out to a medical expert to talk through your options or better yet, when you hit the supplement aisle, just keep walking."