Updated: July 24, 2019
Butylated hydroxytoluene or BHT also known as dibutylhydroxytoluene, is a lipophilic organic compound, chemically a derivative of phenol, that is useful for its antioxidant properties. It is a lab-made chemical that is added to foods as a preservative.
With this usage BHT maintains freshness or prevents spoilage; it may be used to decrease the rate at which the texture, color, or flavor of food changes. People also use it as medicine. BHT is widely used to prevent oxidation in fluids (e.g. fuel, oil) and other materials where free radicals must be controlled. BHT is used to treat genital herpes and acquired immunodeficiency syndrome (AIDS). Some people apply BHT directly to the skin for cold sores. BHT is an antioxidant. It may damage the protective outer layer of viral cells. This may keep the viruses from multiplying and/or doing more damage.
More evidence is needed to rate the effectiveness of BHT for these uses.
BHT is safe in the amounts found in processed foods. But there isn't enough information to know if it is safe to take BHT in medicinal doses, which are typically higher. There also isn't enough information to know whether BHT can be safely used on the skin. The US Food and Drug Administration classifies BHT as generally recognized as safe (GRAS) as a food preservative when used according to approved uses. However, there could be a possible link between BHT and cancer risk, asthma, and behavioral issues in children. Some studies show a potential to increase risk and some to decrease risk.
BHT is safe when eaten as food, but there's not enough information to know if it's safe in the larger amounts that are used as medicine. If you are pregnant or breast-feeding, avoid using it as medicine.
The appropriate dose of BHT depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for BHT. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.