What is it?
Hydroquinone is a skin-lightening agent used to treat hyperpigmentation, including melasma, sun spots, post-inflammatory pigmentation, and uneven skin tone. It works by inhibiting the activity of tyrosinase, an enzyme involved in melanin production. By slowing down melanin synthesis in the skin, hydroquinone helps fade existing dark spots and prevent new ones from forming.
Available in both prescription and over-the-counter strengths, it is often recommended as part of a targeted pigmentation routine. It is usually applied directly to affected areas once or twice daily, often in combination with other ingredients such as retinoids, kojic acid, or vitamin C, which help boost its efficacy and improve overall skin texture and tone.
How is it used?
Hydroquinone is widely studied and has long been considered one of the most effective topical treatments for stubborn pigmentation. However, its use is not without controversy. Long-term or inappropriate use can lead to side effects such as irritation, redness, or dryness, especially in those with sensitive skin. More rarely, overuse has been linked to exogenous ochronosis, a condition that causes paradoxical darkening of the skin, particularly in darker skin tones. For this reason, hydroquinone is often used in short cycles (for example, three months on, one month off) and under the supervision of a skincare professional.
In many countries, hydroquinone is only available by prescription. In the EU, Australia and Japan, it has been banned from over-the-counter sale due to concerns about misuse or unsupervised long-term application. Despite this, it remains a gold standard in dermatology for managing pigmentation disorders when used correctly and in a well-formulated routine.
Because hydroquinone can make the skin more sensitive to the sun, daily use of broad-spectrum sunscreen is essential. Sun exposure without protection can worsen pigmentation and counteract treatment progress.
