Over-the-counter products can contain 0.5% to 2% concentrations. At the pharmacy, 4% concentrations of hydroquinone (and sometimes even higher) are available by prescription only. A concentration of 12% hydroquinone actually prevents the production of melanin altogether.
However, while The Spot Cream is generally safe, one of the high-strength ingredients in a few of the formulas is hydroquinone, which could rarely lead to some serious health risks. And while Musely's 60-day Result Guarantee sounds generous, it's quite strict and requires a commitment to regular mobile app check-ins.
They will use a cream with no more than 4% hydroquinone in conjunction with the frequent application of an SPF 30 sunscreen for the best results. Solutions of 2% are the most readily available, while 4% hydroquinone creams can only be prescribed in the most challenging cases.
Hydroquinone is used to lighten the dark patches of skin (also called hyperpigmentation, melasma, "liver spots," "age spots," freckles) caused by pregnancy, birth control pills, hormone medicine, or injury to the skin. This medicine works by blocking the process in the skin that leads to discoloration.
“There's also a phenomenon called ochronosis, or increased pigmentation/darkening of the skin that is caused by hydroquinone in high concentrations and with long-term use,” she explains. “It is safe to use in 2% to 4% formulations twice a day for 12 weeks max. Then skin then needs a break from the chemical.”
In most cases, lightening of skin should be seen after four weeks of treatment.
Hydroquinone. Topical HQ is regarded as the gold standard for the treatment of facial hyperpigmentation. HQ is a bleaching agent that acts by inhibiting tyrosinase to limit melanin production in the skin.
Hydroquinone and Retin-A (Tretinoin)
When used with Hydroquinone, it can speed up the process of fading hyperpigmentation. These two ingredients can be found together in compound preparations or used as separate products for more control.
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.
Rarely ochronosis - ochronosis is a blue-black or gray-blue discoloration; it is rare and more commonly seen in patients that use a high concentration of hydroquinone for a long period on large areas of the body.
Tretinoin is an anti-aging powerhouse, meaning it should have no problem dispatching fine lines and wrinkles. It does not work for deeper wrinkles. Hydroquinone doesn't work at all against fine lines and wrinkles, so stick to the collagen-boosting power of tretinoin.
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.
Hydroquinone was available previously in over-the-counter products and is currently available in prescription formulations with common concentration ranges of 0.4 to 5%. Prescription strengths available in the United States include hydroquinone 2% and 4% cream and hydroquinone 2% gel.
In most cases, lightening of skin should be seen after 4 weeks of treatment. Sometimes it may take longer to see any change but if no bleaching effect is seen after 3 months of treatment, you should stop using hydroquinone. Hydroquinone is an over-the-counter drug that may be used in concentrations of up to 2%.
According to research, ochranonsis is a condition that might occur following long-term application of skin-lightening creams containing hydroquinone. Ochranosis may cause darkening of the skin, instead of fading a particular spot. Long-term use of Hydroquinone creams may also lead to exogenous ochronotic lesions.
Avoid irritants: Be mindful of other skincare products or ingredients that may potentially irritate your skin. Avoid using harsh cleansers, exfoliants, or other products that can cause irritation or sensitivity while using hydroquinone.
The U.S. Cosmetics Ingredients Review Panel indicates that hydroquinone is unsafe for use in products that are left on the skin, but because of lax enforcement, directions for skin-lightening products containing hydroquinone encourage frequent and consistent use on the skin.
However, it's also possible that the 2 percent strength of hydroquinone isn't strong enough for you. Concentrations over 2 percent (up to 4 percent) are available only by prescription. Also, sunlight can reverse the effect of hydroquinone, so you need to stay out of the sun.
Kojic acid
Kojic acid has skin-lightening properties that can help reduce the appearance of dark patches associated with melasma. It inhibits the production of melanin, the pigment responsible for skin color10.
Other side effects include skin irritation and redness. HQ is the first-line treatment for several hyperpigmentation conditions, including melasma, chloasma, freckles, age spots, and post-inflammatory hyperpigmentation caused by acne or trauma [15]. HQ is most often used at concentrations of 2-4% [16].
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.
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.