Things GNC Sells That Are Not Actually Good For You

GNC is a popular vitamin and supplement shop. For the uninitiated, walking into a GNC can be overwhelming. The shelves are lined with pill bottles, dark canisters, and, well, usually very buff dudes. Navigating the store's website may be easier — or harder — depending on how you shop. You can navigate by your goals, but each goal offers a slew of options that can be hard to narrow down. Since the FDA treats supplements differently than drugs, safe and forthcoming ingredient labels are hard to come by, even when the ingredients are listed (via American Cancer Society).

A 2015 study in the New England Journal of Medicine found that an average of 23,000 visits to the emergency room every year are due to adverse reactions to supplements. As the study highlighted, it's true that not all supplements are safe. Yes, even the ones you can find at GNC may not actually be good for you. Here's a look at some of these products.

Nugenix and other testosterone boosters are popular among men who love the gym life. Testosterone and other hormone replacement therapies can be incredibly valuable when supervised by a doctor, explained WebMD. But when over-the-counter supplements start popping up, experts recommend you think twice before using them. This is because many over-the-counter testosterone supplements have little to no evidence to back up their claims (via WebMD).

Synthetic variations of testosterone exist, and while they are also helpful when prescribed by a doctor, many abuse them. And that can lead to lasting health repercussions. Without obtaining a legal drug, you can buy a testosterone booster, such as Nugenix Maxx, at GNC. These supplements are marketed as "testosterone boosters" and contain a mixture of vitamins with scant evidence proving that they actually work as intended.

According to Science Daily, many of these ingredients and vitamins in these boosters are included in higher volumes than is safe to consume. Plus, less than 25% of the supplements studied were actually able to boost testosterone levels. This may not be the absolute worst thing sold at GNC, but it is an expensive waste of money.

As of this writing, GNC sells over a dozen L-glutamine supplements online. While L-glutamine is not harmful exactly, it seems to be one of the less useful supplements sold at GNC. Glutamine is one of the 20 amino acids, and it is the only one that has two molecular forms, L-glutamine and D-Glutamine. L-glutamine is one of the non-essential amino acids, which means that it is naturally produced in the body (via WebMD). In fact, L-glutamine is one of the most abundant amino acids that is naturally produced within our muscles. 

Although glutamine can be useful for certain people — like those with HIV, AIDS, or IBS – there is no evidence to support that supplementing this amino acid can increase athletic performance, although it is often marketed that way. In fact, overusing L-glutamine can result in nausea, vomiting, joint pain, and hives (per Healthline). Additionally, Healthline revealed that some cancers "increase rapidly in response to L-glutamine." The article continued, "For this reason, it may be advised for those with cancer, or with high risk of cancer, to avoid supplements."

Capsaicin is a component that is naturally found in cayenne peppers and other spicy peppers. Capsaicin is the source of the uncomfortable burning you feel after eating a spicy pepper. This specific spicy element has been proven to be an appetite suppressant. Ongoing studies are proving that capsaicin has anti-inflammatory properties. Experts recommend consuming it in raw form, although eating peppers instead of supplementing can provide you with ultra-healthy antioxidants, too (via Healthline).

The Herbal Plus Cayenne Pepper capsules are one of the more affordable supplements available at GNC. This is awesome, but not when you compare it with buying an actual cayenne pepper, which is available for less than a dollar in grocery stores. Plus, ingesting too much capsaicin can lead to gastrointestinal distress.

One of the main side effects of supplementing capsaicin is a burning sensation along the entire length of your GI tract, that is, mouth all the way to the exit, people (per Healthline). The benefits of capsaicin can best be reaped by incorporating spicy peppers into your diet, no pill form necessary, explained WebMD.

Chitosan with glucomannan is a tongue-twister if we've ever heard one. The logic behind the popularity of this supplement is somewhat of a brain-twister as well. Chitosan is derived from the exoskeletons of crustaceans. These crustaceans include shrimp, lobsters, and clams, according to WebMD. Chitosan is marketed as a wonder drug that can reduce the amount of fat your body absorbs in the intestinal tract.

According to the GNC website, the Total Lean brand of chitosan is said to "help promote a feeling of fullness," which is likely due to the psyllium husk included in the concoction. Psyllium husk is a naturally occurring compound proven to aid in weight loss (via Medical News Today).

Chitosan does not occur naturally in foods, as it is extracted from the hard shells of sea creatures and some insects. No dosage standards have been set, and the quality and quantity available in each formulation vary, WebMD explained. Chitosan is generally only unsafe for people with shellfish allergies and those who take bloodthinners. But since none of the weight-loss benefits have yet been proven, this is yet another supplement that isn't worth shelling out the cash for. The experts at WebMD instead encourage consumers to talk to their doctors to avoid any potentially harmful drug interactions.

Products formulated with garcinia cambogia, like Sports Research Garcinia Cambogia, are marketed as a stimulant-free way to obtain more energy and burn fat by simply existing. Garcinia cambogia is a compound that is found in the rind of Malabar tamarind, a tropical fruit. The active ingredient is hydroxy citric acid, which scientists believe can raise serotonin levels and decrease the sensation of hunger (via WebMD).

However, there is a dark side to this seemingly innocuous tropical fruit. In 2017, the FDA released a statement saying that garcinia cambogia is unsafe and linked to serious liver issues (WebMD). Additionally, garcinia cambogia has the potential to interact poorly with popular painkillers, diabetes medications, and psychiatric drugs.

Though this naturally occurring chemical compound can act as an appetite suppressant, the numbers proving actual weight loss are not promising. Plus, experts recommend skipping the magic bullet and hiring a personal trainer instead.

Pre-workouts are extremely popular, which is unsurprising since they are basically made up of copious amounts of habit-forming caffeine. The most popular variations sold at GNC include Cellucor C4 Ultimate Pre-Workout and BSN N.O. -XPlode, which contain 300 milligrams and 275 milligrams per scoop, respectively.

Pre-workouts are potentially harmful because of the sheer amount of caffeine they contain (via Fox 25). The average 8-ounce cup of coffee contains around 95 milligrams of caffeine, though the type of beans and roast may affect the actual amount (per Healthline). Drinking coffee in the morning and then a pre-workout before hitting the gym can potentially lead to overconsumption of caffeine. The side effects of overconsumption are unpleasant but not usually life-threatening and include extreme jitters, nausea, vomiting, cramps, and high blood pressure. In very rare cases, pre-workout has caused cardiac arrest (via Fox 25).

Even GNC warns that the Cellucor pre-workout it sells is "only intended for healthy adults, 18 years of age or older" and advises buyers to "consult a licensed, qualified, healthcare professional" before taking. When used in moderation, pre-workout can assist you in getting a good pump. But with all of the extra, unregulated ingredients floating around, the experts at Healthline urge you to caffeinate with caution.

Not to be confused with the legit amino acid L-glutamate, L-carnitine is an amino acid-like substance. It is similar to a chemical compound that is produced in the human body, explained WebMD. L-carnitine has been FDA-approved to treat kidney and other diseases. However, its effect as a fitness supplement has been underwhelming at best, as research has shown.

The GNC website states that the Beyond Raw Chemistry Labs brand of L-carnitine "facilitates the metabolism of long-chain fatty acids and helps transport them in your body." But a study published in the International Journal of Sport Nutrition and Exercise Metabolism PubMed study noted that supplementation of L-carnitine has no effect on substrate utilization or athletic performance.

In case you aren't nerds about exercise physiology like us, "substrate utilization" can be loosely explained as follows: When you are doing slow, steady-state workouts, your main source of energy (substrate) is fat. Conversely, when you perform high-intensity work, carbohydrates are the main source of fuel for utilization. Ultimately, L-carnitine isn't bad for you. But it is yet another supplement sold at GNC that isn't worth your hard-earned cash.

It would be negligent to avoid the glaring red flag within GNC's Bpi Health Keto Weight Loss product description. It clearly states that "electrolytes ... may be depleted during a ketogenic diet."

If you have not yet heard about the latest fad diet, allow us to introduce you to the ketogenic diet. The theory behind it is to severely limit carbohydrates. If you do not provide your cells with their preferred fuel source, carbs, your body will react by using its second favorite source of fuel, fat. If you maintain this state for long enough, your body will become efficient at this, which is "ketosis" (via Healthline).

The keto diet is effective for weight loss, though it is not considered sustainable. And what about the supplements? Well, they may work to a degree, but as Barbara Gower, a professor of nutrition sciences at the University of Alabama at Birmingham, told Insider, "The results of studies on keto supplements are inconsistent, and marginal at best," says Gower. They're also pretty unnecessary. Ariana Fiorita, a registered dietitian at the Center for Functional Medicine at Cleveland Clinic, told the publication, "Keto pills and drinks can be costly and oftentimes contain all of the ingredients that you would have at home already."

The product description for Trace Minerals Colloidal Silver on GNC's website instructs consumers to use it "until desired results are attained." So, what, we wonder, could these desired results be?

The National for Complementary and Integrative Health describes colloidal silver as tiny silver particles in a liquid, sometimes promoted as a dietary supplement. Colloidal silver is often marketed as a magic-bullet type of substance. Manufacturers often claim it can prevent infections, treat congestion, and boost your immune system. It has also been rumored that colloidal silver can aid in treating HIV and AIDS, cancer, herpes, shingles, and eye problems. Yet, no research exists to support these claims, confirmed WebMD.

In fact, consuming colloidal silver can be downright dangerous. The FDA has been warning against the effects of colloidal silver since 1999. The most common side effect is argyria, which is the bluish-grey discoloration of the skin, according to the National Center for Complementary and Integrative Health. Colloidal silver can also interfere with many medications, making it a danger to many. As it is not an essential mineral and could, in fact, be harmful, you should consider avoiding colloidal silver altogether.

GNC's marketing of Jarrow Formulas Wild Bitter Melon Extract may give you pause. The product description reads: "Supports blood pressure and blood sugar already in the normal range." So, If it's in the normal range, one could argue a supplement is not needed.

Bitter melon appears so fresh and wonderful, but just like our girl Britney, bitter melon is not that innocent. Most of the research done on bitter melon has been inconclusive. Many researchers believe that it may help your cells use and move glucose. But plenty of researchers concede that more tests should be executed before further claims are made (via Healthline). 

Bitter melon's side effects are fairly aggressive and worth noting. According to Healthline, the side effects can include nausea, vomiting, diarrhea, anemia, liver damage, contractions, vaginal bleeding, and even abortions. With the stakes of the side effects that high, we don't think we'll be popping over to GNC to buy bitter melon extract any time soon. 

TBH, there is nothing truly unhealthy about Goli Nutrition Apple Cider Vinegar Gummies. But there isn't anything especially healthy about them either (via Bustle). Apple cider vinegar is widely viewed as a safe and healthy product to ingest. And researchers have proven that munching ACV gummies won't harm your health, but they are unsure if chomping is as effective as swigging (per Bustle).

Goli gummies include 500 milligrams of apple cider vinegar, which is made up of 5% acetic acid. Acetic acid is the common component of most vinegar and is thought to be the cause of the health benefits, explained Bustle. However, these gummies that GNC sells include cane sugar, as well as many additives that are common in gummy candy. Since experts are unsure about the effects of ACV in gummy form and each one contains 4 unnecessary grams of carbohydrates, we'll pass. We prefer our gummy bears without the salt-and-vinegar chip vibe, anyway.

While Hydroxycut may be popular and yes, we may have even tried it in the past, it is problematic on a few levels and really should be avoided at all costs. The two main ingredients that experts take issue with are the green coffee extract and the Yohimbe extract.

WebMD says that Yohimbe, which masquerades under a few different pseudonyms, can cause increased blood pressure, rapid heart rates, headaches, liver and kidney problems, seizures, panic attacks, heart problems, and death. While it may not seem like much, the 56.3 milligrams per serving in MuscleTech Hydroxycut Hardcore Elite is a lot of any substance that lists death as a very possible side effect.

While green coffee extract is widely used as a stimulant, Medline Plus revealed that there is insufficient evidence to prove that it reduces the symptoms of a litany of diseases. Green coffee extract is sourced from unroasted coffee beans and is said to have weight loss properties. The same study contains an incredibly long list of medications that green coffee extract may interact it. This seems like reason enough to take our coffee beans roasted and combined with milk in the form of our daily latte.