Citric Acid

INCI: Citric Acid

Also known as: AHA, Citrus Acid

ExfoliantsexfoliantbotanicalAnecdotal evidencePregnancy safe

Skinlumis Rating

Comedogenic

0/5

Irritancy

2/5

Best applied

Effective range

0.1%–10%

How It Works

An AHA found in citrus fruits. More commonly used as a formulator's pH adjuster than as a standalone active.

Loosens corneodesmosomes at low pH and chelates metal ions. Provides antioxidant action via tricarboxylic structure.

pH Range

2.0–3.5

Benefits

pH adjustment
Mild exfoliation
Antioxidant
Chelator

Proven For

What the evidence supports.

Dullness

Best For

All skin types

Avoid If

No notable contraindications reported.

Layering Order

3/10

Apply early in routine, toner/essence step.

Max Safe Concentration

10%

Concentration range in well-formulated products: 0.1%–10%

Seasonal Use

Year-round.

Nutrition Connection

Oranges, lemons, limes, grapefruit.

Skin Signals When You Need It

No specific deficiency signals tracked for this ingredient.

For Estheticians & Professionals

Usually appears as a pH adjuster, not as a marketed active.

Clinical Evidence

The research behind Citric Acid.

4 peer-reviewed studies

Every claim on this page traces to published research. Findings below are drawn from randomized trials and systematic reviews, each links to the study on PubMed.

Systematic Review

Oral collagen peptides at 2.5-10g daily significantly improved skin elasticity and reduced wrinkle depth after 8-12 weeks across 11 RCTs.

Choi FD, Sung CT, Juhasz MLW, Mesinkovska NA
Journal of Drugs in Dermatology, 2019

View Study →

Systematic Review

Estrogen deficiency following menopause causes 30% reduction in skin collagen within the first 5 years.

Wilkinson HN, Hardman MJ
Maturitas, 2017

View Study →

Systematic Review

Chronic psychological stress elevates cortisol, accelerating skin aging through collagen degradation and barrier disruption.

Chen Y, Lyga J
Inflammation and Allergy Drug Targets, 2014

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Randomized Controlled Trial

Nano-hyaluronic acid significantly improved skin hydration and elasticity after 8 weeks.

Jegasothy SM, Zabolotniaia V, Bielfeldt S
Journal of Clinical and Aesthetic Dermatology, 2014

View Study →

Pairs Well With

Lactic AcidVitamin C

Conflicts With

No flagged conflicts. Still, patch-test new actives.

Your Skin Compatibility