Tretinoin:
In adults and elderly patients, tretinoin should be applied daily at night. Just enough cream should be used to cover the affected areas thinly. Once the maximum effect has been achieved (after about 3 - 6 months) it can be maintained by continuing to apply tretinoin cream one to three times a week.
This product can make your skin more sensitive to the sun so you should avoid sunbathing or sunbeds. You should also always use a sunblock recommended by your practitioner to help prevent further sun damage to your skin.
In medical trials, the only adverse reaction to the cream was skin irritation. Mild to moderate skin reactions (e.g. dryness, peeling, redness, burning, stinging, and itching) are seen in many patients when they start this treatment. If this occurs, patients are usually recommended to stop treatment for a few days, and then start treatment again with a tiny pea sized amount spread over the area to be treated.
Tretinoin is a pharmaceutical product that is only available on prescription from a doctor or surgeon in the U.K.. It is possible to purchase some prescription drugs, including tretinoin, directly from the internet without a doctor’s prescription. We would, however, strongly advise you not to begin using this product without first seeing a specialist.
Hydroquinone:
This product is available in low strengths of 2% or less, by itself, or in combination with other products such as alpha hydroxy acids, without a prescription. Higher strengths require a prescription from a suitably qualified practitioner.
Hydroquinone can cause skin irritation with itching and redness, which can make it unsuitable for some patients.
It must be used alongside a high factor sunblock, and should not be used for more than a few months without a break of at least a month owing to the potential risk of developing a condition called ochronosis (This is a abnormality in our metabolism which can result in the surface of the skin of the face, as well as in the whites of the eyes, becoming a brownish colour.) This is especially important in people with black skin.
As with tretinoin, it is possible to purchase some of these creams over the internet without a prescription, but you are strongly advised not to start using hydroquinone without first seeking the advice of a specialist.
People with black skin are not advised to use lightening creams since they can cause a very dramatic and ugly change of skin colour where they have been applied. The cream leaves irregular white or dark patches, which are hard to cover up. There is no safe way to lighten dark skin permanently.