Acesulfame-K (Ace-K)

An artificial sweetener. It has been linked to insulin resistance and high blood sugar.

Aspartame (Nutrasweet, Equal)

An artificial sweetener. It has been linked to insulin resistance and high blood sugar.

Banned substances (By international athletic federations)

Includes more than 200 substances (including anabolic agents, narcotics, and growth hormone secretagogues) that will disqualify an athlete from competition.

Benzoic acid

Artificial preservatives. When mixed with vitamin C it can yield benzene, which is carcinogenic.

Butylated hydroxyanisole (BHA)

An artificial antioxidant preservative. Carcinogenic, it accumulates in the lungs, liver, and kidneys and is associated with stomach tumors in animal studies.

Butylated hydroxytoluene (BHT)

An artificial antioxidant preservative. Carcinogenic, it accumulates in the lungs, liver, and kidneys and is associated with stomach tumors in animal studies.

BPA - Bisphenol A

A plasticizer used in water bottles and other plastic containers. It mimics estrogen in the body and can disrupt thyroid hormones, causing infertility, miscarriage, erectile dysfunction. Also can adversely influence fetal development and increase cancer risk.

Colors derived from artificial sources (FD&C colors, etc.)

Artificial colors and food dyes are made from chemicals derived from petroleum. There are concerns about the safety of using artificial colors in foods - including risks linked to cancer, hyperactivity, and allergies.

Cyclamates

Artificial sweeteners. They are allowed in Canada and Europe but banned in the U.S. (where the FDA has not found evidence of safety). Studies have associated them with bladder tumors in rodents and testicular atrophy and sperm disruption in monkeys

DMSO (Dimethyl Sulfoxide)

Artificial sweeteners. They are allowed in Canada and Europe but banned in the U.S. (where the FDA has not found evidence of safety). Studies have associated them with bladder tumors in rodents and testicular atrophy and sperm disruption in monkeys

DMSO (Dimethyl Sulfoxide)

A chemical that dissolves many organic and inorganic substances. Some DMSO on the market may actually be industrial grade and may contain a number of impurities that can easily be absorbed into the skin with potentially serious health effects.

Ephedra sinica (Ma Huang)

A botanical used in Traditional Chinese Medicine. It contains ephedrine, which was used and abused in weight loss products and banned in the U.S. Ephedra abuse can cause increased blood pressure, heart rate, and possibly heart attack and stroke.

Ethylene glycol

A clear, viscous liquid primarily used in industrial manufacturing applications, and is an ingredient in products like automotive antifreeze and coolant. Ethylene glycol is also found in some inks, detergents, and cosmetic products. Ethylene glycol is toxic if ingested.

Erythritol

A type of sugar alcohol, which is used as a sugar replacement and/or low-calorie sweetener. Can be found in sugar-free jellies, candy, chewing gums, and toothpaste.

Ethyl vanillin

Artificial vanilla flavor more potent than vanillin, used to give chocolate a vanilla flavor. It is manufactured from petrochemicals and has been reported to cause allergic reactions and headaches in sensitive individuals.

Ethylene oxide (ETO)

Used to sterilize food, botanicals, and spices. The World Health Organization (WHO) classifies ETO as a Class 1 carcinogen. It is highly toxic to kidneys, liver, and nerves and is banned in the U.S.

FD&C numbered color pigments

Artificial colors and dyes. They often contain aluminum, sometimes contain lead and mercury, and have been linked to cancer, hyperactivity, and allergies.

Ferric oxide (red, black)

Ferric oxide, also known as iron(III) oxide, is a common ingredient in some supplements, particularly as a color additive in tablets and capsules. It can also act as an iron supplement, though it's not always the most bioavailable form.

Flavors derived from artificial sources (vanillin, etc.)

Artificial flavors are lab-made flavorings, a combination of chemicals synthesized to smell and taste similar to natural flavorings. Various side effects have been linked to artificial flavors, such as headaches, fatigue, chest pain, dizziness, and allergic reaction.

Formaldehyde

A colorless, flammable gas at room temperature that has a strong odor. Formaldehyde is used in some household products and can also be used as a preservative in some products, including medicines and cosmetics. Exposure may cause adverse health effects.

Glycols (propylene glycol)

Used as solvents, sweeteners, and preservatives. They are allergenic and are a toxic to the kidneys, liver, and nervous system, and even more toxic to infants, who metabolize them slowly.

Gluten

Contained in wheat, rye, and barley. Wheat is one of the 8 common allergens. Wheat and other gluten-containing foods are associated with Celiac disease and less sever gluten intolerances.

High fructose corn syrup (HFCS)

A sweetener made from corn starch. It is a major contributor to fatty liver, metabolic syndrome, obesity, diabetes, and inflammation, and can be contaminated with mercury.

Hydrogenated/modified oils (brominated oils, etc.)

Oil fillers in softgel. Examples include partially hydrogenated soybean oil. Because trans-fats are associated with heart disease, stroke, diabetes and inflammation, the FDA removed them from its Generally Recognized As Safe list in 2015.

Iron oxide

A metal mixture that modifies structural and magnetic characteristics. Iron oxide can be harmful through inhalation, causing respiratory issues and prolonged skin or eye contact can cause irritation or staining.

Irradiated ingredients

Used to sterilize foods and botanicals. It is controversial because of the lack of long-term safety studies, and it has been banned for use in dietary supplements in the United States.

Mineral oil

Chemical substances prepared from naturally occurring crude petroleum oil. They have been classified as Group-1 carcinogens (sufficient evidence to cause cancer in humans).

Parabens (propylparaben, methylparaben, etc.)

Parabens, commonly used as preservatives in cosmetics and personal care products, are associated with potential health concerns like endocrine disruption, reproductive issues, and increased cancer risk. While research on the extent of these harms is ongoing, some studies suggest parabens can mimic estrogen, potentially affecting hormone balance and contributing to breast cancer development. They may also cause skin irritation and allergic reactions in some individuals.

Petrolatum

Topical protectant and lubricant. Ingesting petrolatum, especially in large amounts, can cause stomach upset or diarrhea.

Potassium bromate

Oxidizing agent that has been used as a food additive and may be carcinogenic in humans.

Polyethylene glycol (PEGs)

Coating on tablets. Used to make tablets smooth and easier to swallow, it is often contaminated with carcinogens, including 1,4, dioxane, ethylene oxide, and polycyclic aromatic compounds.

Polysorbate

Commonly used as emulsifiers, can pose potential health risks, particularly due to contamination with 1,4-dioxane and ethylene oxide, which are known carcinogens. Additionally, polysorbates can cause skin irritation, allergic reactions, and may disrupt the gut microbiome.

Preservatives derived from artificial sources (BHA, BHT, EDTA, TBHQ, etc.)

Artificial preservatives can pose health risks, including triggering allergic reactions, contributing to hyperactivity, and potentially increasing the risk of certain cancers. Some preservatives, like nitrates, can form carcinogenic compounds under certain conditions. Additionally, artificial preservatives can sometimes make digestion more difficult and may weaken heart tissue.

Propionates

Artificial preservatives can pose health risks, including triggering allergic reactions, contributing to hyperactivity, and potentially increasing the risk of certain cancers. Some preservatives, like nitrates, can form carcinogenic compounds under certain conditions. Additionally, artificial preservatives can sometimes make digestion more difficult and may weaken heart tissue.

Propyl gallate

A synthetic antioxidant preservative. It is a carcinogen, and can also induce asthma, stomach irritation, and possible endocrine disruption.

Propylene glycol

A synthetic liquid substance that absorbs water and maintains moisture in certain medicines, cosmetics, and food products. Some people may experience skin irritation or contact dermatitis from frequent exposure to propylene glycol. This exposure could be through cosmetic products, food, or topical medications.

Saccharin (Sweet 'N Low, Sugar Twin)

An artificial sweetener. It can cause bladder cancer in animals, and there are no strong studies proving safety in humans (only observational). As a sulfonamide it can also cause allergic reactions.

Sodium benzoate

An artificial preservative. When mixed with vitamin C it can yield benzene, which is carcinogenic.

Sulfites (as an additive)

Preservatives. Although they can occur naturally in foods, they are often added in manufacturing. They are allergenic and can cause severe asthmatic reactions in sulfite-sensitive individuals.

Synthetic Vanillin

Artificial vanilla flavor. Natural vanillin is a constituent of vanilla. However, synthetic vanillin is used in imitation vanilla flavoring and is generally manufactured from petrochemicals. Another is from genetically modified yeast. It may trigger allergic reactions, GI upset, or migraines.

Talc

A naturally-occurring mineral used in some consumer products, including personal care products like cosmetics. Pure talc and talc-containing rock are mined from the earth. Talc is made up of magnesium, silicon, oxygen and hydrogen. While generally considered safe, concerns exist regarding potential health risks, particularly when talc is contaminated with asbestos.

Tertiary butylhydroquinone (TBHQ)

A synthetic antioxidant related to BHA and BHT. It is tumorogenic and neurotoxic, and can cause liver enlargement.

Titanium dioxide

A metallic colorant that makes ingredients white. It has been classfied by the International Agency for Research on Cancer as a Class 2B carcinogen (i.e., "possibly carcinogenic to humans").