Will hydroquinone help with dark spots?

Hydroquinone works to suppress the production of melanin pigments, which cause blemishes and acne scars, and is an ingredient that can be expected to have a whitening effect.
Hydroquinone is an ingredient found in foods such as strawberries and coffee, but since its skin-whitening effects were discovered, it has begun to be used in cosmetics.
Its whitening effect is said to be 10 to 100 times that of kojic acid or arbutin, and it also works to protect the skin from damage caused by ultraviolet rays and other factors.

Combined with tretinoin for improved effectiveness
Tretinoin is an ingredient that is used in combination with hydroquinone.
Tretinoin is a derivative of vitamin A that promotes skin turnover.

Some people say that when hydroquinone is used alone, it has a low penetration rate into the skin and the whitening effect is not easily felt, but it is said that the penetration effect can be increased by using it in combination with tretinoin.
Applying tretinoin first will allow the hydroquinone to penetrate more easily, making it more effective.

Will my spots get darker while using hydroquinone?
Melanin pigment originally absorbs ultraviolet rays and protects the skin from damage, but when the melanin pigment is lost by applying hydroquinone, the skin becomes more susceptible to damage from ultraviolet rays.
Be sure to use sunscreen during the day to protect your skin from UV damage.

Strict Regulations in the United States <br data-mce-fragment="1">There was a time when hydroquinone was the mainstream for skin whitening in the United States, but now store-bought cosmetics are limited to containing a maximum of 2% of the compound, and any higher than that is only permitted under a doctor's supervision.

In Japan, the concentration of hydroquinone that can be used in cosmetics is not regulated, and high-concentration skin care products are available commercially.
The higher the concentration, the more effective it is, but long-term use also increases the risk of side effects such as "vitiligo", so we recommend that you receive guidance from a clinic and use it according to your skin condition.