What Are the Negative Effects of Weight Gainers?

Weight gainer and muscle mass gainer side effects include a long list of health risks.
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Muscle mass gainer and weight gainer products promise increases in muscle size and claim to make it easy to pack on the pounds. However, in most cases, if you eat a healthy diet, nutritional supplements aren't needed. It's more important to know that the products can have harmful health effects.


Gainer supplements come in shakes, powders and other forms, and their components vary. Protein is the main ingredient, but some products include creatine. It's important to keep in mind that the Food and Drug Administration doesn't review these supplements for safety or efficacy. Consult a doctor before taking any gainer product.

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Weight gainer and muscle mass gainer side effects include a long list of health risks. Some are minor, but many are serious.

Supplemental Nutrition Drinks

Of all the products for weight gain on the market, supplemental nutrition drinks are probably the safest. Sold under brand names like Ensure or Boost, they're found on supermarket shelves. According to Harvard Health, the drinks help people who are recovering from an illness, have a poor appetite or experience difficulty chewing.

Supplemental nutrition drinks provide a balanced intake of carbohydrates, proteins and fats. Some are designed to meet the nutritional needs of specific conditions such as cancer, diabetes or kidney disease. The products have some drawbacks, but the pros outweigh the cons in people who find it difficult to eat enough.

One problem is that the drinks contain quite a bit of sugar. While the extra sugar can lead to weight gain, which is the goal, in some people, it can result in too much weight gain. This increases the risk of conditions related to being overweight such as diabetes and high blood pressure. In people who are capable of eating, the extra calories may be too risky, says Harvard Health.


Another concern is that nutrition derived from a can can't compare to nutrition derived from food. Although many of the drinks are fortified with vitamins and minerals, they lack some of the nutrients found in whole foods

A healthier alternative is to purchase a food-based shake, which is found in the refrigerated section of supermarkets. They're less processed and contain less added sugar. Another advantage is that they're unlikely to have excessive quantities of vitamins or unnecessary ingredients, which are contained in the canned drinks.


Before selecting a shake, read the label. If sugar is the first or second ingredient listed, the product contains too much, states Harvard Health.

Side Effects of Protein Powder

Some weight gainer side effects and mass gainer side effects stem from the protein content. Athletes and people wanting to gain weight tend to think the consumption of extra protein will increase muscle mass. MedlinePlus says this is actually a myth: only strength training builds muscle.



Eating an excessively high-protein diet is linked to an array of negative health effects, so taking protein supplements or consuming more than the recommended protein intake in foods isn't recommended.

Taking protein supplements on a long-term basis has adverse consequences, indicates a study published in Nature Metabolism in April 2019. It found the products cause imbalances in amino acids, which are the building blocks of protein. Consequences include overeating, obesity and lower longevity.


Authors of a May 2018 review featured in the Journal of Dietary Supplements said the purported benefits of protein supplements have led to overuse. After analyzing the pros and cons, they said that the products often don't contain other essential nutrients needed for health. People should get protein from food unless enough quantity isn't available in the diet, they concluded.

Harvard Health reports additional problems associated with protein supplements. Some products have a milk-based protein source, which can cause intestinal distress in people who are lactose intolerant or have dairy food allergies. Other products are high in sugar, a problem that can lead to blood sugar spikes.


Research has found a broad range of toxins and contaminants in protein powders, notes Harvard. These include heavy metals, such as lead, mercury and arsenic, along with pesticides and bisphenol-A, a chemical linked to cancer.

Unless you have a medical condition that makes it difficult to take in sufficient nutrients, get your protein from food, advises Harvard. Good sources include beans, nuts, seeds, low-fat dairy foods, eggs, fish, poultry and lean meats.


Side Effects of Creatine

Creatine, an amino acid stored in muscles, is sometimes added to muscle mass gainers. Manufacturers claim it boosts energy, so it's of interest to bodybuilders and athletes. But studies on its efficacy show inconsistent results, notes the Mayo Clinic.


When taken at recommended doses, creatine is considered safe. Side effects include dizziness, nausea, dehydration, fever, water retention, muscle cramping, diarrhea, heat intolerance, weight gain and gastrointestinal pain. The supplement may also exacerbate mania in bipolar disease. When taken at high doses, creatine can damage the kidneys, heart and liver, states Mayo Clinic.

Side Effects of Other Ingredients

A study published in the British Journal of Cancer in March 2015 discovered a link between muscle-building supplements containing creatine or androstenedione and testicular cancer. Reporting on the findings, the Harvard T.H. Chan School of Public Health said the risk is greater in men who start using the supplements before age 25 or who have used the supplements for three years or longer.

If you use a muscle mass gainer, you need to be aware of the dangers of anabolic steroids, a common ingredient in such products. They can cause serious liver injuries, says the FDA. In addition, they have been associated with severe acne, aggression, hair loss, depression and changes in mood.

Anabolic steroids have also been linked to life-threatening reactions, including strokes, heart attacks, kidney damage, blood clots in the deep veins and blood clots in the lungs.

Due to the potential for serious problems, if you take a muscle mass gainer with steroids or steroid-like agents, you should stop immediately, warns the FDA. Also, let your doctor know if you're experiencing symptoms that could be due to the products. These include shortness of breath, weakness, chest pain, fatigue, fever, nausea, abdominal pain, discolored urine or a yellow tinge to the skin.

Some products, such as Serious Mass, contain maltodextrin, an additive with a high glycemic index. People with diabetes should avoid these muscle gainers.




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