PoreWise La Roche-Posay · Serums
Effaclar Ultra Concentrated Anti-Acne Serum
Product
- Brand:
- La Roche-Posay
- Product type:
- Serums
- Last checked:
- 2026-10-30
- Formula version:
- Pack label · 2026-10-30 on the brand's Singapore product page (Asian formula)
- Fragrance & alcohol:
- Contains fragrance · Contains alcohol (denatured)
19 ingredients on this list · WATER at number 1 · Denatured Alcohol at number 2 · PROPANEDIOL at number 3
Product description
A leave-on exfoliating serum for blemish-prone skin: glycolic acid and salicylic acid, plus capryloyl salicylic acid (a lipophilic salicylate), with niacinamide, buffered with sodium hydroxide. Alcohol denat. is second on the list and the formula is fragranced.
Brand's own claims
The brand's own claims, quoted from its own material.
Full ingredient list
Kept exactly as the source printed it, including spelling in the original.
- 1 WATER
- 2 ALCOHOL DENAT.
- 3 PROPANEDIOL
- 4 GLYCOLIC ACID
- 5 NIACINAMIDE
- 6 DIMETHYL ISOSORBIDE
- 7 PENTYLENE GLYCOL
- 8 SALICYLIC ACID
- 9 SODIUM HYDROXIDE
- 10 PEG-60 HYDROGENATED CASTOR OIL
- 11 HYDROXYETHYLPIPERAZINE ETHANE SULFONIC ACID
- 12 CITRIC ACID
- 13 PEG-30 GLYCERYL COCOATE
- 14 CAPRYLOYL SALICYLIC ACID
- 15 BIOSACCHARIDE GUM-1
- 16 MALTODEXTRIN
- 17 PHYTIC ACID
- 18 POLYQUATERNIUM-10
- 19 PARFUM
Original label text
AQUA / WATER ● ALCOHOL DENAT ● PROPANEDIOL ● GLYCOLIC ACID ● NIACINAMIDE ● DIMETHYL ISOSORBIDE ● PENTYLENE GLYCOL ● SALICYLIC ACID ● SODIUM HYDROXIDE ● PEG-60 HYDROGENATED CASTOR OIL ● HYDROXYETHYLPIPERAZINE ETHANE SULFONIC ACID ● CITRIC ACID ● PEG-30 GLYCERYL COCOATE ● CAPRYLOYL SALICYLIC ACID ● BIOSACCHARIDE GUM-1 ● MALTODEXTRIN ● PHYTIC ACID ● POLYQUATERNIUM-10 ● PARFUM / FRAGRANCE
Ingredient analysis
NIACINAMIDE · Actives · NIACINAMIDE · Barrier lipids · PROPANEDIOL · Humectants
Barrier lipids
1Lipids that occur naturally in the skin barrier (ceramides, cholesterol, fatty acids).
Humectants
3Bind water and draw it into the upper layers of the skin.
Exfoliants
3Loosen the bonds between corneocytes so dead cells shed.
pH adjusters
3Bring the formula to, and hold it at, its target pH.
Solvents
5Dissolve or carry other ingredients.
Emulsifiers
2Keep oil and water mixed in a stable formula.
Other
3Use on the ingredient list: see the product ingredient list.
Evidence
- Skin effect Human trial Certainty: Moderate Primary source
In a randomized, placebo-controlled split-face study of 30 healthy Japanese women, a cosmetic containing 4% niacinamide reduced the skin-surface average roughness (Ra) value significantly more than the niacinamide-free control site after 8 weeks (P<0.05).
Who it applies to: Skin-surface roughness measured by replica profilometry (Ra).
Study limits: Measured at the eye area on a photoaged/wrinkle cohort; the endpoint is surface roughness.
- Skin effect Human trial Certainty: Moderate Primary source
In 20 people with Fitzpatrick skin types IV-V, a broad-spectrum sunscreen containing sclareolide and niacinamide significantly prevented experimentally induced post-inflammatory hyperpigmentation: in stripped, exposed zones the protected skin improved by +5.96 ITA degrees versus -9.88 in unprotected skin (net protection about 16 ITA degrees, p < 0.001).
Who it applies to: People with darker skin phototypes (IV-V) prone to post-inflammatory hyperpigmentation, applying the sunscreen daily for 20 days under UV and visible-light exposure.
Study limits: Small sample (20), within-subject controlled model of experimentally induced pigmentation; the abstract calls for comparative studies with and; industry involvement.
- Skin effect Human trial Certainty: Moderate Primary source
In 72 women with visible signs of ageing, a niacinamide-containing biomimetic lamellar cream significantly improved the Cutometer R5 elasticity parameter, wrinkle score, TEWL and corneometer values over 4 weeks compared against the untreated side.
Who it applies to: Women with visible signs of ageing, applying the cream twice daily for 4 weeks.
Study limits: Grading of high-resolution images failed to detect improvements in skin texture; proof-of-concept studies.
- Skin effect Human trial Certainty: Moderate Primary source
In 91 women with melasma, a skincare routine containing vitamin B3 (niacinamide) and 2-mercaptonicotinyl glycine significantly reduced MASI after 3 months, with roughly 38-41% reduction by 6 months.
Who it applies to: Women aged about 44 with melasma, phototypes III-IV, using the routine twice daily with daily SPF50+ sunscreen.
Study limits: A clinically relevant difference favoured Kligman's triple combination in the first 3 months; industry-funded; skin radiance and fine wrinkles also improved.
- Skin effect Human trial Certainty: Moderate Primary source
In a randomized, double-blind, placebo-controlled split-face trial of 52 Taiwanese subjects, 4% niacinamide alone significantly reduced instrument-measured pore counts at week 8, and 4% niacinamide with 0.03% kinetin produced persistent significant reductions in pore, spot, wrinkle and evenness counts at weeks 8 and 12.
Who it applies to: Instrument-measured facial pore counts over 8-12 weeks.
Study limits: The niacinamide-group showed significant pore reduction at week 8; 'pore counts' is an instrument parameter.
- Skin effect Human trial Certainty: Moderate Primary source
In a double-blind, placebo-controlled trial of 100 Japanese subjects, a 2% niacinamide moisturiser significantly lowered sebum excretion rate after 2 and 4 weeks; in a separate 30-person Caucasian split-face study it significantly reduced casual sebum level after 6 weeks.
Who it applies to: Adults with facial sebum concerns applying a 2% niacinamide moisturiser for 2 to 6 weeks; measured with sebumeter-based sebum excretion rate and casual sebum level.
Study limits: The effect differs by measured endpoint and population.
- Skin effect Human trial Certainty: Moderate Primary source
In 40 people with mild-to-moderate acne all using topical benzoyl peroxide plus adapalene, a moisturiser with ceramides and niacinamide significantly improved non-inflammatory, inflammatory and total acne lesions on that side of the face versus a hydrophilic cream after 8 weeks, and decreased cutaneous irritation.
Who it applies to: People on topical anti-acne medication who add a moisturiser alongside treatment, in a split-face, double-blind, randomized design for 8 weeks.
Study limits: All participants used prescription/OTC anti-acne drugs (5% benzoyl peroxide + 0.1% adapalene). TEWL, hydration, sebum, pH and other biophysical measures stayed close between the two creams. This is adjunctive care.
- Skin effect Human trial Certainty: Moderate Primary source
In a 12-week randomized, double-blind half-face study, a combination of 4-hexylresorcinol and niacinamide improved hyperpigmentation spots (L*), the appearance of fine lines and wrinkles, and skin firmness significantly more than niacinamide alone.
Who it applies to: Chinese adults using the combination cream twice daily for 12 weeks in a split-face design.
Study limits: Industry-funded (Unilever R&D); part of the evidence comes from in-vitro melanocyte and 3D skin models.
- Skin effect Human trial Certainty: Low Primary source
A facial moisturiser containing niacinamide improved stratum corneum barrier function and skin hydration, measured instrumentally, in people with rosacea over four weeks of twice-daily use.
Who it applies to: A leave-on facial moisturiser, applied twice daily for four weeks, in adults with rosacea.
Study limits: The tested article was a finished moisturiser. Fifty participants, one centre, four weeks. The study measured barrier function and hydration.
- Skin effect Human trial Certainty: Low Primary source
In a randomized split-face controlled trial in people with rosacea-associated erythema and sensitive skin, a dermocosmetic containing mineralizing water, probiotic fractions, hyaluronic acid and niacinamide significantly improved erythema at day 15 (p<0.01) and day 30 (p<0.001), with skin erythema, tightness, dryness, hydration and TEWL improving versus the untreated side (p<=0.05).
Who it applies to: Facial erythema, tightness, dryness, hydration and TEWL over 30 days.
Study limits: The comparator is usual skin care / an untreated half-face.
- Skin effect Human trial Certainty: Low Primary source
In an open randomized, vehicle-controlled trial of 48 people with mild-to-moderate facial seborrheic dermatitis, 4% nicotinamide cream once daily for 12 weeks reduced the combined erythema/scaling/infiltration score by 75% from baseline versus 35% with the vehicle (p<0.05).
Who it applies to: Combined clinical score of erythema, scaling and infiltration over 12 weeks.
Study limits: Open-label.
- Skin effect Human trial Certainty: Low Primary source
In 30 women with melasma or post-inflammatory hyperpigmentation, a serum combining lotus sprout extract, tranexamic acid and niacinamide reduced skin tone unevenness by 38% and 33% respectively over 16 weeks (P < 0.008).
Who it applies to: Women with melasma or PIH, 70% with Fitzpatrick skin types IV-VI, applying the serum twice daily for 16 weeks.
Study limits: 30 participants; "skin tone unevenness" is a sponsor-defined endpoint.
- Skin effect Human trial Certainty: Moderate Primary source
In 83 adults with comedones, a serum containing salicylic acid and lipohydroxy acid significantly improved open comedones on the nose, closed comedones on the face, skin pore density, sebum secretion and skin hydration from baseline after 8 weeks; adding a mask improved closed comedones more than the serum alone (-6.56 vs -5.19, p = 0.022).
Who it applies to: Adults in Shanghai with comedones, PIE and PIH, using the serum for 8 weeks.
Study limits: Both groups used active products; improvements were reported against baseline and between the two active groups. Industry-funded. This is the trial found that counted open and closed comedones separately.
- Skin effect Clinical guideline Certainty: Moderate Primary source
The 2024 American Academy of Dermatology acne guideline lists topical salicylic acid as a conditional recommendation. Strong recommendations in the same guideline go to benzoyl peroxide, topical retinoids, topical antibiotics and oral doxycycline.
Who it applies to: Acne vulgaris in people aged nine and older, as covered by the guideline's scope.
- Skin effect Review article Certainty: Low Primary source
Against topical tretinoin, salicylic acid showed similar values in overall acne improvement (RR 1.00, 95% CI 0.92 to 1.09; one trial, 46 participants). The review graded the certainty of that finding as low.
Who it applies to: Topical salicylic acid for mild to moderate acne. Most participants in the review were 12 to 30 years old, and most studies ran longer than eight weeks.
Study limits: The review covers 49 trials with 3880 participants, salicylic acid appears in a small part of them: 41 to 86 participants per comparison. Every salicylic acid comparison was graded low or very low certainty.
- Skin effect Human trial Certainty: Very low Primary source
In a 21-day prospective study of 42 people with mild-to-moderate acne and oily or combination skin, a salicylic-acid-containing gel used twice daily was associated with a 23.65% fall in sebum, a 40.5% rise in skin hydration, a 49.26% fall in transepidermal water loss and a 23.81% improvement in acne grade (all P < 0.05 except IGA P < 0.001).
Who it applies to: Sebum, skin hydration, transepidermal water loss and acne grade over 21 days in people with oily or combination skin.
Study limits: One centre, 21 days, 37 of 42 participants were women, and the research group was affiliated with the product maker.
- Skin effect Brand claim Certainty: High Public database
Salicylic acid is a keratolytic: it loosens the bonds between dead skin cells so they shed.
Who it applies to: Acne and keratolysis, at the concentrations permitted for cosmetic use.
Study limits: Most evidence comes from leave-on acne treatments. A cleanser is on the skin for a minute. · Finding · SALICYLIC ACID
- Irritation Review article Certainty: Very low Primary source
Trials of topical salicylic acid for acne reported application-site reactions such as scaling and redness.
Who it applies to: Topical salicylic acid in acne trials, mainly leave-on use over eight weeks or longer.
Study limits: The review graded the salicylic acid adverse-event comparisons as very low certainty.
- Skin effect Human trial Certainty: Moderate Primary source
In a prospective, randomized, evaluator-blind, split-face trial of 20 patients with acne vulgaris, two 50% glycolic acid + 0.5% salicylic acid peels significantly reduced total lesion count (P<0.001) and produced fewer side effects than Jessner's solution.
Who it applies to: Patients with acne vulgaris receiving two 50% glycolic acid + 0.5% salicylic acid peels 2 weeks apart (one side vs Jessner's solution on the other).
Study limits: Small sample (20) and a combination peel (glycolic + salicylic acid); this is a procedural peel.
- Skin effect Human trial Certainty: Moderate Primary source
In a 2-week double-blind split-face study of 37 participants, a biphasic serum with 10% glycolic acid delivered 45.52% greater exfoliation (p<0.001) and improved skin brightness, texture and hydration versus the comparison side.
Who it applies to: Healthy participants using a 10% glycolic acid biphasic serum on one side of the face for 2 weeks.
Study limits: Short duration (2 weeks) and a single product formulation; the study measured exfoliation and cosmetic parameters.
- Skin effect Human trial Certainty: Low Primary source
In 23 women, a single application of a 4% alpha-hydroxy acid solution combined with negative-pressure physical action significantly reduced whitehead and blackhead counts at 1, 2 and 4 weeks, and reduced pore area and number at week 1, compared with AHA peeling alone.
Who it applies to: Healthy women receiving a single in-clinic application in a randomised split-face design, assessed at 1, 2 and 4 weeks.
Study limits: The intervention was a single in-clinic chemical peeling plus negative-pressure physical action.
- Skin effect Human trial Certainty: Moderate Primary source
In a double-blind, vehicle-controlled trial of 30 people with two or more solar lentigines, a serum with 10% L-ascorbic acid and 2% phytic acid lowered the pigmentation index of the treated lesions over three months while the vehicle-treated lesions stayed stable (P <= 0.003 from month 1 to month 4). Six adverse events, mostly halo depigmentation, were judged possibly related to the product.
Who it applies to: Pigmentation index, dermoscopic pigmentation and brightness (L*) of solar lentigines over three months, with two months of follow-up.
Study limits: The serum combines two actives. Each person applied the product to one side of the body and the vehicle to the other. 30 people, and six halo-depigmentation events were possibly related to the product. The authors call for larger studies.
Related skin concerns
Skin concerns with evidence for ingredients on this list.
Formula history
1 version of this formula on record.