The reactivity of hydroquinone's hydroxyl groups resembles that of other phenols, being weakly acidic. The resulting conjugate base easily undergoes O-alkylation to give mono- and diethers. Similarly, hydroquinone is highly susceptible to ring substitution via Friedel–Crafts alkylation.
Hydroquinone has no known severe, serious, moderate, or mild interactions with other drugs.
Hydroquinone can cause mild irritant contact dermatitis when used in concentrations above 4%. A short drug holiday and/or application of a topical steroid will usually settle the reaction. Commercial formulations of hydroquinone contain the preservative metabisulphite, which can cause an allergic reaction.
Some commercially available topical formulations of hydroquinone contain sulfites that may cause allergic-type reactions, including anaphylaxis and life-threatening or less severe asthmatic episodes, in certain susceptible individuals.
In all formulations, hydroquinone is unstable turning brown upon contact with air. Once the hydroquinone has oxidized, it is no longer active and should be discarded.
Hydroquinone has a pretty short shelf life. After a couple of months, it can start to break down and lose its potency, meaning it becomes less effective.
FDA has received reports of serious side effects including skin rashes, facial swelling, and ochronosis (discoloration of skin) from the use of skin lightening products containing hydroquinone.
Avoid using hydroquinone with peroxide products such as benzoyl peroxide or hydrogen peroxide, which can cause discoloration. 3. Avoid alpha hydroxy acids. The combination of hydroquinone and alpha hydroxy acids (AHAs) can irritate your skin.
The lesions may develop gradually over 6 months to 3 years or longer. [8] Two recent case reports from India mention the occurrence of EO with use of 2% hydroquinone preparations for 7–8 years.
Hydroquinone frequently causes irritations like itchiness and redness in skins that are barrier-compromised or sensitive, which can be the case for any skin type. The most common side effects are irritation, redness, stinging, and inflammation.
With continued use, hydroquinone and mercury can build up in your body, which may cause harm. The FDA has received reports of serious side effects from the use of hydroquinone, including rashes, facial swelling, and permanent skin discoloration (ochronosis).
Alternative lightening agents including mequinol, arbutin, kojic acid, and others have shown comparable efficacy to hydroquinone in treating hyperpigmentation with less concerning side effects.
With GRAS (Generally Recognized as Safe) status, hexylresorcinol is a great choice for beauty brands seeking to provide skin lightening and even toning benefits in their next skin care formula. Hexylresorcinol was introduced to the skin care market in 2007 under the trade name Synovea® HR.
You may not see significant improvement until 2 to 6 months after starting use. Hydroquinone can be applied morning and night. excess pigmentation such as the neck and back of hands. Allow product to fully absorb into skin before applying moisturizer or any other skin care products.
However, 4% Hydroquinone is a better topical hypopigmenting agent with rapid rate of clinical improvement when compared to 0.75% Kojic Acid cream. The side effects of both the hypopigmenting agents were not significant.
This disease entity may be first noticed in newborns as their urine may be darker than normal. People are often without symptoms until later in life when the skin, sclera (white part of the eye), ears, and nose may develop pigmentary changes. Ear wax of a person with ochronosis will also be dark in color.
We recommend taking a 2 month break after 3 months of application. Since hydroquinone is a photosensitive agent, It is also important to use SPF 30 or higher daily when on hydroquinone.
As a rule, you should stop using hydroquinone after 3-6 months of continuous use. This is because prolonged use of hydroquinone can lead to adverse effects on the skin, such as ochronosis, skin irritation, and sensitivity. There are several signs that it may be time to stop using hydroquinone.
2.2. 2 Oxidation of hydroquinone Hydroquinone is oxidized by a variety of oxidants including nitric acid, halogens, persulfates and metal salts (NIOSH, 1978). It is also oxidized by molecular oxygen in alkaline solutions. Hydroquinone reacts with molecular oxygen (autooxidation).
Arbutin has been found to be the most effective active ingredient in our study, even more so than hydroquinone, despite being a naturally occurring derivative.
Combination Tip: Combining hydroquinone with Vitamin C may improve overall efficacy, but due to potential sensitivities, this combination should only be used under the supervision of a dermatologist. Sunscreen: How It Works: Sunscreen is essential for preventing further hyperpigmentation caused by UV exposure.
You need a doctor's prescription to buy hydroquinone cream online or in a physical pharmacy. You can have a online consultation with a dermatologist. After the consultation they will issue a prescription containing for hydroquinone cream if it's safe and medically appropriate for you.