Introduction

Skin aging results from intrinsic aging and extrinsic factors such as ultraviolet radiation, pollution, and lifestyle habits, leading to wrinkles, pigmentation changes, and reduced skin elasticity. Retinoic acid is a standard anti-aging therapy but is often associated with irritation. L-ascorbic acid (LAA) has antioxidant and collagen-promoting properties and may offer a safer alternative; however, comparative clinical data against retinol are limited. 

Aim

To evaluate the effectiveness and safety of topical L-ascorbic acid (LAA) 15% serum compared with retinol 0 .1% serum in improving skin aging parameters. 

Patient Profile

• Adults aged 35-65 years 
• 30 participants enrolled; 27 completed the study and were included in the final analysis. 
• Majority were female (86.7%), with the largest age group being 41-45 years (36.7%). 

Methods

Study Design

• Randomized, double-blind, split-face clinical trial. 
• Simple randomization assigned either LAA or retinol to the right or left side of the face. 
• 30 patients were enrolled, 27 completed the study. 

Treatment

• One facial side received LAA 15% serum.
• Contralateral facial side received retinol 0.1% serum.
• Follow-up assessments at Week 2 and Week 4. 

Study Endpoints

Primary effectiveness assessments

• Modified Dermoscopy Photo Aging Scale (DPAS).
• JANUS-III skin analysis parameters: 
  • Pores
  • Elasticity
  • Wrinkles
  • Pigmentation
  • UV-induced pigmentation
  • Skin tone
  • Sebum
  • Porphyrin
  • Moisture 

Safety Assessment

• Recording of subjective and objective adverse effects throughout the study. 

Results

Baseline DPAS Findings

• Superficial wrinkles were the most common dermoscopic finding. 
• Hypo-/hyperpigmented macules were frequently observed. 

No participants presented with yellowish discoloration, yellowish papules, or criss-cross wrinkles

Figure 1: Most prevalent photoaging features at baseline using DPAS

              

Modified DPAS Outcomes

• Both treatments significantly improved photoaging scores (Modified DPAS) from baseline.
• LAA 15% serum: Significant improvement at Week 2 (p=0.005) and Week 4 (p=0.002).
• Retinol 0.1% serum: Significant improvement at Week 2 (p=0.022) and Week 4 (p=0.040).
• No significant difference was observed between LAA and retinol in DPAS scores at baseline (p=0.708), Week 2 (p=1.000), or Week 4 (p=0.749).

Table 1. Comparison of DPAS Scores Between Treatment Groups

Time Point	LAA Median (IQR)	Retinol Median (IQR)	p-value
Week 0	2 (1-4)	2 (1-4)	0.708
Week 2	2 (1-3)	2 (1-3)	1.000
Week 4	2 (1-4)	2 (1-3)	0.749

 DPAS = Dermoscopy Photo Aging Scale; IQR = interquartile range. 

JANUS-III Outcomes

Significant Changes from Baseline to Week 4

LAA Group

Pigmentation, UV pigmentation, and sebum levels increased significantly (p=0.004, p<0.001, and p=0.005, respectively). 

Retinol Group

Pigmentation, UV pigmentation, sebum and porphyrin levels increased significantly (p=0.009, p<0.001, p=0.001, and p=0.025 respectively),

Table 2: Comparison of JANUS-III Parameters on Week 4 Between LAA and Retinol Groups

Parameter	LAA	Retinol	p-value
Pores	46.63	46.59	0.985
Elasticity	57.07	57.11	0.994
Wrinkles	16.15	14.93	0.496
Pigmentation	27.15	27.0 (10.0)	0.788
UV Pigmentation	19.44	21.26	0.467
Skin Tone	50.70	51.1	0.673
Sebum	193.0 (294.0)	276.0 (416.0)	0.115
Porphyrin	28.30	28.30	1.000
Moisture	25.67	25.52	0.944

JANUS-III data are reported as mean or median (IQR). 

Safety 

• Adverse effects occurred in 5 of 27 participants, including stinging and itching with LAA and stinging with retinol.
• All events were mild, self-limiting, required no treatment, and resolved within 24 hours. 

Conclusion

• Topical L-ascorbic acid 15% serum demonstrated anti-aging efficacy comparable to retinol 0.1%, with similar improvements in DPAS or JANUS-III outcomes.
• Compared with retinol, L-ascorbic acid showed superior tolerability, making it a suitable option for patients with sensitive skin, barrier dysfunction, rosacea, inflammatory dermatoses, pregnancy considerations, or retinoid intolerance.
• Considering its efficacy, safety, patient acceptance, and real-world feasibility, L-ascorbic acid represents a rational and accessible option for both initial and maintenance anti-aging therapy

Reference 

Dermatol Rep. 2026 doi: 10.4081/dr.2026.10293