hydroquinone

Hydroquinone is a depigmenting agent used to treat dyschromia, a condition of skin discoloration or patches of uneven skin color. Hydroquinone is an organic compound naturally found in many plants including coffee. Hydroquinone was originally used as an industrial product and its skin-lightening properties were accidentally discovered in 1938, after which it was studied for clinical use in skin conditions that cause dyschromia.

Hydroquinone works by inhibiting the synthesis of melanin, the pigment that is responsible for the color of the hair, skin and the iris in the eye. When applied to the skin, hydroquinone suppresses the activity of melanocytes in the skin, which produces melanin. Hydroquinone works in two ways:

• Inhibits DNA and RNA synthesis in melanocytes, preventing the formation of melanosomes, the organelles in melanocytes that synthesize and store melanin
• Inhibits tyrosinase, an enzyme essential for melanin synthesis

The effects of hydroquinone, however, are reversed with its discontinuation and sun exposure. Hydroquinone is used to treat dyschromia caused by:

• Freckles
• Melasma or chloasma, a condition of excessive pigmentation caused by UV damage or hormonal changes during pregnancy
• Solar lentigines, known as sun spots or liver spots, from repeated sun exposure
• Hyperpigmentation caused by inflammatory skin conditions such as eczema, dermatitis, acne and burns

Hydroquinone was readily available on prescription and over the counter until 2020, however, as per reforms under the Coronavirus Aid, Relief and Economic Security (CARES) Act, skin lightening products containing hydroquinone need to be approved by the FDA before they can be legally sold. In the U.S., currently, the only available product containing hydroquinone is Tri-Luma, a combination product containing fluocinolone, hydroquinone, and tretinoin.

• Do not use hydroquinone in the following conditions:
  • Hypersensitivity to hydroquinone or any of its components
  • For hair removal (depilation)
  • Treatment of sunburn
• Some hydroquinone formulations may contain sulfites and may cause allergic reactions

Common side effects of hydroquinone include:

• Mild skin irritation
• Burning and stinging
• Allergic contact dermatitis
• Redness (erythema)
• Dryness of skin
• Inflammation

Rare side effects of hydroquinone include

• Blue-black or gray-blue discoloration (ochronosis)
• Complete depigmentation
• Splotchy depigmentation

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug.

Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

Topical cream

• 2%
• 4%

Lotion

• 2%

Emulsion

• 4%

Topical Solution

• 2%
• 3%

Topical Gel

• 2%
• 4%

Reduction of Melanin Hyperpigmentation

• Adults and children over 12 years: Apply a thin layer to affected areas and rub in thoroughly every 12 hours
• Children under 12 years: Safety and efficacy not established

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• Hydroquinone has no known severe, serious, moderate, or mild interactions with other drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

• Controlled studies of hydroquinone use during pregnancy do not show an increased risk for fetal harm, however, there is significant systemic absorption with topical application; use with caution in pregnant women
• It is not known if hydroquinone is present in breast milk; use with caution

• Limit hydroquinone application to areas no larger than arms, hands, face, and neck
• Exposure to sunlight can reverse effects; exercise caution
• Do not apply near eyes, or on cut, abraded, or sunburned skin, or over prickly heat rash (miliaria rubra)
• Do not apply on skin soon after shaving or using a depilatory agent