Throw away any hydroquinone product that turns brown. This means the hydroquinone became oxidized and is no longer active. Contact a physician if you experience any severe side effects.
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 Once the hydroquinone has oxidized, it is no longer active and should be discarded.
No, the hydroquinone won't hurt you if it turns brown but it won't be effective either because it has oxidized or degraded. I would recommend throwing it out after a year or sooner, if it turns brown throughout the tube.
A hydroquinone is a compound with two hydroxyl (OH) groups bound to aromatic carbons, which can be reversibly oxidized by 2 electrons to a quinone (with two double bonded oxygens), which makes this family of compounds useful in electron transport chains.
An antioxidant system, most commonly the combination of sodium sulfite and sodium metabisulfite, is added to HQ formulations to stabilize HQ, which is otherwise sensitive to oxygen and light.
Tips when using hydroquinone:
Throw away any hydroquinone product that turns brown. This means the hydroquinone became oxidized and is no longer active. Contact a physician if you experience any severe side effects.
Oil Control
Managing excess sebum production is key to preventing oxidation of blocked pores. Use oil-free or mattifying products formulated to absorb excess oil and keep your skin looking matte and fresh.
Expires 6 months after preparation. Store your medication in the fridge between 2°C to 8°C. Do not freeze.
Hydrogen peroxide may be generated by the reaction of hydroquinone and oxygen, and can then react with p-benzoquinone forming 2,3-epoxy-hydroquinone. This latter product, if reduced, forms 2-hydroxy-hydroquinone.
Hydroquinone's lightening effects are generally visible after 4 weeks of treatment, though some conditions may require a longer treatment plan. If no visible changes occur after 3 months of treatment, you should stop using hydroquinone and consult with your dermatologist about alternative treatment options.
INGREDIENTS CAN OXIDIZE:
Generally, you can tell that something has oxidized because it will turn a yellow-ish or brown-ish color. Sometimes this color shift doesn't greatly impact the efficacy of the product. But sometimes, this oxidation can be a sign that the ingredients inside the product are no longer potent.
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.
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.
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. Other ingredients with a brief life span are benzoyl peroxide and salicylic acid, often found in products designed to treat acne, as well as vitamin C and retinol.
Hydroquinone will change from a creamy color to dark yellow or brown as oxidation occurs, making it less efficacious. Therefore, any products with color change should be replaced. We feel that hydroquinone applied topically as a thin layer one to two times daily for up to 3 months has a good safety profile.
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.
Properties. Hydroquinone is an aromatic compound consisting of the benzene ring and two –OH groups at para position. It is available in the form of white crystals, but industrial use grades may be light grey or light tan. Contact with air and light causes oxidation and darkening of color.
Hydroquinone alone did not affect body weight or bladder weight.
Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids. Hypochlorous acid is unstable and it easily dissociates to form nascent oxygen.
Hydroquinone's FAQ. Is Hydroquinone safe to use on my face? Yes, however, specialists recommend its use only in particular areas with hyperpigmentation. Minor side effects are still possible.
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.
Should I apply hydroquinone or tretinoin first? According to Dr. Mohta, if you are using two separate medications, you should apply hydroquinone in the evening after applying tretinoin.
The older we get, the more our skin cells are damaged by external oxidising agents caused by UV irradiation. This explains the loss in elasticity our skin undergoes as it ages, and the subsequent wrinkles and fine lines that form as our skin is unable to bounce back into position.
The most noticeable changes in the skin are flaccidity, fine lines, deepening of wrinkles and dryness. On the other hand, the so-called extrinsic aging is the result of action of many environmental factors such as chronic sun exposure and pollution.
Oxidation or degradation of ingredients isn't always harmful, but it can make them less effective, Dr. Chapas said. “Even if it's not going to be harmful to you, it might not be that beneficial to you either,” she added.