Janssen Retino A Micro 0.1% Gel

This is why tretinoin is so effective; it gets to work immediately on the skin.

Research on tretinoin has found it to be incredibly effective for reducing the signs of aging. It helps improve damage from the sun, even the skin tone, and smooth out wrinkles. It is also an effective acne treatment by reducing and balancing out sebum production in pores.

Tretinoin, like other forms of Vitamin A, increases the turnover cycle of skin cells. This helps the skin create newer and healthier skin cells faster.

It can cause irritation, redness, and dry skin because it is considered a "strong" ingredient. Those with sensitive skin should consult a professional about using tretinoin.

Using retinoids will increase sun-sensitivity in the first few weeks of use. Though studies show retinoids increase your skin's natural SPF with continuous use, it is best to always wear sunscreen and sun-protection.

Read about a form of retinoid you can purchase at the store, retinol.

This ingredient is also pretty picky about pH; it performs best at pH 6.5 or below.

At the right pH level, sorbic acid is "active" and can slip through the outer wall of a microbe. Once inside, it turns the cell's interior more acidic to shut down the microbe from the inside.

The EU caps this ingredient at 0.6% while the CIR has concluded it's safe at concentrations up to 1%. It's most often used around 0.05-0.2% in cosmetics.

Though this ingredient is considered low-sensitizing and well-tolerated, a very small number of people may have a contact allergy to it. Be sure to patch test if you have a history of allergies towards preservatives.