Erythrulose is a carbohydrate, which is used in combination with dihydroxyacetone (DHA) in many self-tanning products because of its natural ability to dye the skin. It is a pale-yellow liquid extracted from red berries. This sugar reacts with the amino acids of the keratin found in the dead skin cells of the upper layer.
The reaction, which is completely nontoxic, creates a temporary browning effect on these skin cells. The color change resembles the same colour a UV-based suntan produces.
As the skin sheds naturally in a week or so, the tan begins to wear off. This makes the tan created by erythrulose temporary and completely safe. If properly applied and the skin is kept nourished, the tan can remain for at least 10 days. The tan does not wash away or even sweat off once the complete tone has been developed.
The fading begins gradually as the skin’s normal exfoliation process takes place. The only way the tan will lighten sooner is by intense exfoliation or scrubbing of the skin, prolonged baths or swimming, as well as heavy sweating after a vigorous exercise.
Erythrulose has a composition similar to that of DHA, and the two sugars react on the skin’s surface in a very similar way. However, erythrulose creates a lighter colored tan in a slower time when compared to the tan produced by DHA. The tan created by erythrulose takes up to 24 to 48 hours to fully develop while DHA takes 2 to 4 hours to develop. When it is used alone, the tan it creates fades faster than one created by DHA.
When DHA is used alone, it is likely to produce an orange and streaky tan. But erythrulose has a less drying effect over the skin than DHA does and it provides a smoother fade.
But when these two ingredients are combined, it results in a tan that lasts longer, fades evenly, and produces a deep and natural-looking tan.
Erythrulose is very expensive because it is difficult to obtain. Erythrulose has no side effects and due to its similarity in composition with DHA, it is unlikely for anyone to be sensitive to these two sugars. It reacts only with the skin cells of the upper layer and it does not penetrate below this layer. It is incorporated in sunless tanning products – like spray tans, tanning lotions, tanning gels, bronzers, and tanning mousses – at only 1% to 3%.