Kojic Acid is found naturally in many species of fungi and is also the byproduct made during the fermentation of Sake.
Kojic acid is an anti-pigmentation medicine. It works by suppressing the formation of melanin, a pigment that gives color to the skin.

• Kojic Acid helps in lightening visible spots marks.
• Kojic Acid serves a number of functions beyond skin brightening.
• Kojic Acid is antibacterial, which explains its frequent presence in acne skincare formulations. Because it acts as a skin lightener, it's an effective ingredient for post inflammation hyperpigmentation that can occur from acne lesions. 

• Dry skin,
• Skin burn,
• Skin peeling,
• Erythema (skin redness)

•  It should always be used along with sun-avoidance measures, like using sunscreens and wearing protective clothing.
•  Avoid getting it in your eyes or mouth. If this happens, rinse with water immediately.
•  Do not apply on broken or infected areas of skin. Discontinue use if you experience irritation or allergy and consult your doctor.
•  If you experience any redness, rashes, irritation or stinging sensation when using Kojic Acid, stop using it immediately and consult your doctor.

Arbutin is used by dermatologists as a topical skin lightening agent for treating hyperpigmentation.

It is categorized as a plant extract and a skin lightening agent.

Aside from skin lightening, arbutin also has antioxidant properties that improve skin texture. It’s also used in anti-aging products because of this characteristic.

Arbutin is derived from the leaves of fruits such as bearberry (uva-ursi), pear and cranberry, and it is sometimes made synthetically.

Skin reaction, irritation

If you are using arbutin in a cream or serum, do not apply the product to your whole face.

If you put an arbutin cream or serum on your whole face, you could lighten up non-affected areas.

 Only apply the arbutin serum to the areas on your face affected by hyperpigmentation, and wash your hands after (you probably should be doing this anyways) so you don’t discolor your hands.

Let your arbutin cream or serum fully dry before you applying your moisturizer.

it’s especially important to wear sunscreen because arbutin makes your skin more sensitive to UV rays.

The whitening effect of Arbutin is not permanent.