0.5% A Retinaldehyde | PeptideActive A 0. 5% DNA Repair Serum pH 4. 0 30ml Low irritant Vitamin A works similar to Prescriptive A, without the side effects. More suitable for everyday use, stimulates collagen production, lightens, calms vascular damage, maintains healthy cellular activity and rebuilds structural integrity. Formulated with vitamins B & C, Hyaluronic Acid and powerful anti oxidants for optimal overall tissue function. Additional Information Description: Active A 0.