Ingredient Conflicts
What not to combine
in the same routine
Some active ingredients cancel each other out, and some just stack irritation for no benefit. Below is every conflict pair Skinzy's own routine builder checks for — why each one conflicts, and how to alternate nights instead of dropping either one.
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Adapalene + Benzoyl Peroxide
Benzoyl peroxide oxidizes retinoids on contact, breaking the retinoid molecule down before it can work. Layering them the same night wastes the retinoid entirely and stacks two irritation-prone actives at once for no benefit.
×
Adapalene + Glycolic Acid (AHA)
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Adapalene + Lactic Acid (AHA)
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Adapalene + Mandelic Acid (AHA)
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Adapalene + Salicylic Acid (BHA)
Salicylic acid already penetrates deep into the pore on its own, and a retinoid's turnover effect on top of that strips the barrier faster than skin can rebuild it. Both are genuinely excellent for acne individually — just not stacked in one application.
×
Benzoyl Peroxide + Retinal
Benzoyl peroxide oxidizes retinoids on contact, breaking the retinoid molecule down before it can work. Layering them the same night wastes the retinoid entirely and stacks two irritation-prone actives at once for no benefit.
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Benzoyl Peroxide + Retinol
Benzoyl peroxide oxidizes retinoids on contact, breaking the retinoid molecule down before it can work. Layering them the same night wastes the retinoid entirely and stacks two irritation-prone actives at once for no benefit.
×
Benzoyl Peroxide + Tazarotene
Benzoyl peroxide oxidizes retinoids on contact, breaking the retinoid molecule down before it can work. Layering them the same night wastes the retinoid entirely and stacks two irritation-prone actives at once for no benefit.
×
Benzoyl Peroxide + Tretinoin
Benzoyl peroxide oxidizes retinoids on contact, breaking the retinoid molecule down before it can work. Layering them the same night wastes the retinoid entirely and stacks two irritation-prone actives at once for no benefit.
×
Benzoyl Peroxide + Trifarotene
Benzoyl peroxide oxidizes retinoids on contact, breaking the retinoid molecule down before it can work. Layering them the same night wastes the retinoid entirely and stacks two irritation-prone actives at once for no benefit.
×
Glycolic Acid (AHA) + Retinal
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Glycolic Acid (AHA) + Retinol
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Glycolic Acid (AHA) + Tazarotene
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Glycolic Acid (AHA) + Tretinoin
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Glycolic Acid (AHA) + Trifarotene
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Lactic Acid (AHA) + Retinal
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Lactic Acid (AHA) + Retinol
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Lactic Acid (AHA) + Tazarotene
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Lactic Acid (AHA) + Tretinoin
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Lactic Acid (AHA) + Trifarotene
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Mandelic Acid (AHA) + Retinal
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Mandelic Acid (AHA) + Retinol
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Mandelic Acid (AHA) + Tazarotene
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Mandelic Acid (AHA) + Tretinoin
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Mandelic Acid (AHA) + Trifarotene
Both speed up skin cell turnover and thin the outer skin layer. Used together, the combined exfoliation and increased sun sensitivity go well past what either ingredient produces alone — this is the most common cause of a "retinol burn."
×
Retinal + Salicylic Acid (BHA)
Salicylic acid already penetrates deep into the pore on its own, and a retinoid's turnover effect on top of that strips the barrier faster than skin can rebuild it. Both are genuinely excellent for acne individually — just not stacked in one application.
×
Retinol + Salicylic Acid (BHA)
Salicylic acid already penetrates deep into the pore on its own, and a retinoid's turnover effect on top of that strips the barrier faster than skin can rebuild it. Both are genuinely excellent for acne individually — just not stacked in one application.
×
Salicylic Acid (BHA) + Tazarotene
Salicylic acid already penetrates deep into the pore on its own, and a retinoid's turnover effect on top of that strips the barrier faster than skin can rebuild it. Both are genuinely excellent for acne individually — just not stacked in one application.
×
Salicylic Acid (BHA) + Tretinoin
Salicylic acid already penetrates deep into the pore on its own, and a retinoid's turnover effect on top of that strips the barrier faster than skin can rebuild it. Both are genuinely excellent for acne individually — just not stacked in one application.
×
Salicylic Acid (BHA) + Trifarotene
Salicylic acid already penetrates deep into the pore on its own, and a retinoid's turnover effect on top of that strips the barrier faster than skin can rebuild it. Both are genuinely excellent for acne individually — just not stacked in one application.
×
Pure Vitamin C + Kojic Acid
Ascorbic acid needs a low pH to stay stable, and that acidity destabilizes kojic acid's own structure. Combined, both work less well than either would alone — not a safety issue, an effectiveness one.