Ferrer Internacional Retirides Cream 0.025% Versus Menarini A-Ret Tretinoin Gel 0.025%

You'll likely see it paired with methylparaben to cover the full range (including gram-negative bacteria).

This ingredient is effective at low concentrations (~0.2-0.5%) and stable across a wide pH range (4.5-7.5 pH). It's effectiveness drops off above pH 8 and it can lose potency when combined with non-ionic surfactants like polysorbate 80 due to micellization.

The regulatory bodies have concluded this ingredient to be safe as used in cosmetics. The EU has capped it at 0.14% and combined parabens are not to exceed 0.8%.

While parabens do cross the stratum corneum, only about 1% remains for absorption into the body. This is because most of it is metabolized within living skin.

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.