Any Indoor tanning lotion is predominantly created to enhance or increase the effects of UV (ultraviolet) rays on your skin, as opposed to protecting or even blocking your skin from them as with sunscreens. A key component in these formulas is melanin. According to Wikipedia "melanin is the primary determinant of human skin color". The more melanin in your skin, the darker your skin color will be.
Looking to enhance your natural tan? Or do you want to have that sun bronzed look without the sun? For those people who have the right skin to be able to tan, tanning indoors is seen by many as an intelligent way to minimize the risk of contracting sunburn while maximizing the enjoyment and benefit of having a tan. This is providing there is a sensible control put in place to limit the amount of UVA and UVB rays released through the lamps, together with controlling the amount of time spent in the tanning bed.
Melanogenesis is a term applied to the increased production of melanin in the human skin. UVB radiation, as opposed to UVA radiation, causes DNA damage that in turn stimulates melanogenesis. The resultant, gradual increase in melanin in the skin produces what we call a suntan. The whole melanogenesis process takes time and as such developing a tan becomes a gradual process, not an instant one day wonder. In fact, you will end up with a tan lasting much longer. Many people are impatient though and want a tan after only one day in the sun, or one session in a tanning booth and end up getting sun burnt. A sun burn will end up blistering and peeling and leaving the skin raw and you are back to having no increase in the melanin levels in the skin. This not only leaves no tan, but heightens the risk of skin cancer.
So, for the best tan results, don't treat your tanning like a speed race. Even though you may want that tan yesterday, by overdoing it you will take longer to get to the tan you wanted and because you have acquired a burn as a base (like a scar almost) you will not be able to achieve as dark a tan in the long run.
Tanning is a defensive mechanism. Skin that is not tanned is relatively defenseless against harmful effects of uncontrolled, immoderate exposure to sunlight. Gradually acquiring a higher level of pigmentation is the best protection against basal cell carcinoma. In other words, your body's tan is it's own natural self defense system against any burning by the sun.
An indoor tanning lotion mostly uses ingredients that promote the production of melanin, either by including melanin itself as an ingredient, or by introducing an ingredient that will increase the flow of blood to the skin, thereby increasing the amount of melanin that is brought to the top layers of the skin.
Indoor tanning lotions as a rule, do not contain any sunscreen ingredients and as such offer no protection from the sun. These indoor tanning lotions are sometimes referred to as "tan accelerators" and are designed to be used with tanning beds.
Melanin and L-tyrosine are very common ingredients found in tanning lotions. Other commonly found ingredients include tea oil, copper (in many different chemical compounds), green tea extract and many other natural oils. However, ingredients will vary widely from one brand to another.
Fragrance does not provide any real advantage to the tanning process but of course it makes the whole experience far more pleasant. In fact, when it comes to choosing between any indoor tanning lotion and another it can be the single differentiator. Tanning indoors mean the aroma will be contained and thus far more pronounced than when tanning outdoors. Some people even choose indoor tanning lotions for their aromatherapy qualities.
Another aspect that affects choice of ingredients is that they must not contain such things as mineral oil as this will damage the acrylic surface of the tanning beds. Many outdoor tanning lotions contain mineral oil, or baby oil, and so are not recommended for indoor tanning.
'Tingle' is the de facto standard description for an indoor tanning lotion that contains ingredients that help stimulate the microcirculation of the skin by drawing the blood to the skin's surface. This action causes a tingling sensation on the skin that will vary from one person to another. Whether the increase of blood flow at the skin's surface does actually speed up the tanning effect or not, has not been scientifically proven. Ingredients used to achieve this include irritants or chemicals that cause a reddening sensation and a flushing of the person's skin.
However, there are varying reactions from people to these 'tingle' ingredients, where one indoor tanning lotion may have no effect at all on one person and will actually cause mild pain in another, especially when exposed to the sun. As such, there is no real rating system for tingle and indoor tanning lotions are differentiated as being with or without a 'tingle factor'. So, when using tingle, it is recommended to start at low levels, gradually increasing the levels, while allowing your body to adapt to the stimulation and avoiding any adverse effects.
If an indoor tanning lotion is called a 'Bronzer', it usually contains dihydroxyacetone (DHA). This is usually combined with other ingredients to help tanning. The combination of ingredients is different to sunless tanning lotions though, as the output is not only to provide for an immediate color, but also allow for exposure to UV light. When these bronzing lotions are combined with tingle ingredients they are called Hot Bronzers, or with cooling ingredients like menthol, they are known as Cool Bronzers.
Healthy skin is a vital ingredient when looking to obtain a really great tan. Indoor tanning lotions as well as outdoor ones focus on moisturizing qualities not only while tanning, but for afterwards as well. If the skin is healthy, it has the ability to retain a deeper tan for a longer period of time than if the skin is dry and so more liable to flake and peel. Once the skin is tanned a little, there is an added benefit of being able to build a deeper, darker tan by further exposure either indoors again or outdoors.
Besides moisturizing ingredients, tanning lotions typically include vitamins, natural oils, minerals, essential oils, natural butters, anti-oxidants, and natural botanical extracts (especially aloe vera or aloe ferox). These all aim to help boost the health of the skin and thus your tanning abilities. People who do not use tanning lotions invariably risk drying the skin rapidly, which will release the tanned skin levels in layers - known as 'peeling'.
There are a few products, unofficially known as "All-In-One" that have no tingle and limited amounts of the active sunscreen ingredients that can be used outdoors that actually offer no sun protection factor (SPF). These lotions are used mostly for their moisturizing benefits as well as a small amount of tingle boost to the tanning process. They are really created to be used before and after tanning or as everyday moisturizers for people who tan frequently.
An indoor tanning lotion should carry a warning that they offer no protection from the sun. Whether you choose to avoid the outdoors or not is left up to you. However, this is not at all recommended, as the potential for overexposure is greater when outdoors than in the metered and regulated environment of a tanning salon.