One of the primary purposes for using indoor tanning lotions is to moisturize the skin. This is because tanning (indoors or out) can dehydrate the skin so additional moisturization is needed to compensate and leave the skin looking smooth and healthy. The primary moisturizing ingredients in tanning lotions are essentially the same as in regular hand lotions, although they tend to have less alcohol in them. One of the most popular moisturizing elements in tanning lotions is hempseed oil. This oil is THC-free, so it is legal in the US and has no drug reactions. Because it is high in fatty acids, it helps to seal in moisture and maintain the effects from tanning.
Many indoor tanning lotions now contain bronzers, usually dihydroxyacetone (DHA). This is usually combined with other ingredients to help tanning. This is somewhat different from the use of DHA in sunless tanning, as the goal is to give the user immediate color but they are not avoiding ultraviolet exposure. They are often used to jump start the tanning process. Often the bronzing lotions are combined with other ingredients to give them tingle (Hot Bronzers) or cooling agents like menthol to make them Cool Bronzers.
Some of the active ingredients found in common tanning lotions include melanin and L-Tyrosine. Other commonly found ingredients include tea oil, copper (in many different chemical compounds), green tea extract and many other natural oils. Ingredients vary widely from brand to brand. Most products come in 7 to 8 oz bottles, although some come in 16.9 oz (500 ml) or larger for wholesale salons. The user typically uses between .5 and 1.0 oz per tanning session, spreading liberally over all exposed areas. While fragrance offers no advantage in tanning, it is often one of the most critical elements in which brand a person prefers. This is because most people use tanning lotions in a tanning bed, which is a closed environment, so the aroma of the lotion is much more pronounced than lotions used outdoors. To some, the right lotion will have aromatherapy benefits. Indoor tanning lotions are usually designed to only use ingredients that will not cause damage or build up on acrylic surfaces. This is because all tanning beds use 100% acrylic in their protective shields. This is one reason people should not use outdoor tanning lotion in a tanning bed, as some common ingredients such as mineral oil (also called baby oil) will damage the surface of the acrylics.
Tingle is the de facto standard description for indoor tanning lotions that contain ingredients that increase blood flow at the skin level. This is because the ingredients cause the tanner to experience a tingling sensation (of varying degree). The science behind the concept is more theory than fact, but it is usually accomplished using irritants or chemicals that cause a reddening sensation, flushing the user’s skin. People react differently to the ingredients, and one lotion that has no tingle effect on one person may cause mild pain in another. This is why it is impossible to create a system of rating tingle that is objective. Some companies such as, Australian Gold or Swedish Beauty do offer ratings that offer some guidance to the consumer, but it is not standardized. Most companies produce lotions with and without ingredients that tingle, as many do not prefer this method of tan enhancement or find it uncomfortable.
Most tanning lotions carry warnings that they offer no protection from the sun. Whether this means they should be avoided outdoors would be up to the individual user, although most manufacturers recommend against this as the potential for overexposure is greater when outdoors than in the metered and regulated environment of a tanning bed. There are a few products, unofficially known as All-In-One that have no tingle and limited amounts of the active ingredients that can be used outdoors, but still offer no SPF in them. These are used primarily for their moisturizing benefits as well as mild to moderate amount of boost to the tanning process. They are designed to be used before and after tanning or as everyday moisturizers for people who tan frequently.