Topical Icariin on Acne and Acne Scars

March 4, 2026 updated by: Dae Hun Suh, Seoul National University Hospital

A Study for Evaluating the Effect and Safety of Icariin for Acne and Acne Scars

The goal of this clinical trial is to examine whether topical application of icariin can improve acne and atrophic acne scars in adults. The main questions it aims to answer are:

  • Does icariin reduce the number of facial acne lesions and acne scars?
  • What histological changes occur in acne or scar tissue after using icariin? Researchers will compare icariin to a vehicle control (3% ethanol solution) to assess its relative efficacy.

Participants will:

  • Apply icariin or control solution to each side of the face twice daily for 2 months
  • Visit the clinic every 4 weeks for checkup
  • Receive skin biopsies before and after the study period, if they consent to this procedure

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Acne vulgaris is one of the most common dermatologic conditions, affecting more than 80-90% of adolescents worldwide. Its pathogenesis is multifactorial, involving excessive sebum production, follicular hyperkeratinization, proliferation of Cutibacterium acnes, and inflammation. Clinical manifestations range from comedones and papules to pustules and nodules, most frequently appearing on the face. Beyond the physical burden, facial acne induces significant psychosocial distress, including anxiety, depression, and social withdrawal. Inflammatory lesions frequently progress to atrophic scars, which persist long term and further intensify psychological morbidity. Studies report acne scarring in up to 95% of patients, with approximately 30% developing scars that are severe enough to require clinical intervention.

Current treatments for atrophic acne scars-such as laser resurfacing, chemical peels, microneedling, and soft-tissue fillers-entail risks including pain, prolonged downtime, and variable efficacy. Topical pharmacologic agents, including retinoids, offer noninvasive alternatives, but their scar-remodeling effects are limited and may cause irritation or photosensitivity. Because scar formation involves a complex interplay of inflammation, collagen degradation, and impaired wound healing, there remains an unmet need for therapies that are safe, effective, and accessible, capable of addressing both active acne and established scars.

Icariin is a prenylated flavonoid glycoside isolated from Epimedium species (e.g., Yin Yang Huo, horny goat weed), traditionally used in oriental medicine as an herbal remedy and dietary tincture. It has demonstrated neuroprotective, cardiovascular, anti-osteoporotic, and antitumor effects, and is considered safe for human consumption. Preclinical evidence indicates that icariin inhibits inflammation, regulates lipid metabolism, suppresses bacterial proliferation, and promotes skin wound healing. Despite these properties, which suggest both anti-acne and pro-remodeling potential, no clinical study to date has evaluated icariin's efficacy in human acne or acne scars.

Study Type

Interventional

Enrollment (Actual)

25

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • South Korea
      • Seoul, South Korea
        • Seoul National University Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged 19 to 39 with inflammatory acne and atrophic acne scars on both sides of the face

Exclusion Criteria:

  • Diagnosis of acne conglobata or acne fulminans
  • Pregnancy or breastfeeding
  • Presence of systemic diseases or use of medications that may affect acne or scarring
  • Presence of psychiatric disorders
  • Recent use of isotretinoin within the past 4 months
  • Use of other oral or topical acne treatments or anti-acne cosmetics within the past 2 weeks
  • Receipt of procedural treatment for acne scars (e.g. chemical peels or energy-based devices) within the past 4 weeks

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Icariin
3% icariin
Drug: Icariin
Topical application of 3% icariin solution
Placebo Comparator: Control
3% ethanol
Drug: Vehicle Control
Topical application of 3% ethanol solution

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Change from baseline in the total number of acne lesions and scars at 8 weeks
Time Frame: From enrollment to the end of treatment at 8 weeks
From enrollment to the end of treatment at 8 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Investigator's global assessment for acne (IGA)
Time Frame: From enrollment to the end of treatment at 8 weeks
From enrollment to the end of treatment at 8 weeks
Scar global assessment (SGA)
Time Frame: From enrollment to the end of treatment at 8 weeks
From enrollment to the end of treatment at 8 weeks
Change from baseline in ECCA scar grading scale at 8 weeks
Time Frame: From enrollment to the end of treatment at 8 weeks
The ECCA grading scale (échelle d'évaluation clinique des cicatrices d'acné; a French acronym that translates to Clinical Evaluation Scale for Acne Scars in English) is a tool designed to help dermatologists to assess the severity of acne scars. This score ranges from 0 to 540, with higher scores indicating a more severe condition.
From enrollment to the end of treatment at 8 weeks
Change from baseline in the number of acne lesions and scars by size and type at 8 weeks
Time Frame: From enrollment to the end of treatment at 8 weeks
Acne lesions by type (inflammatory and noninflammatory); acne scars by size (small-sized, < 2 mm; medium-sized, 2-4 mm; large-sized, > 4 mm) and type (icepick, boxcar, and rolling)
From enrollment to the end of treatment at 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Seoul National University Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 21, 2023

Primary Completion (Actual)

December 31, 2025

Study Completion (Actual)

December 31, 2025

Study Registration Dates

First Submitted

July 16, 2025

First Submitted That Met QC Criteria

July 17, 2025

First Posted (Actual)

July 22, 2025

Study Record Updates

Last Update Posted (Actual)

March 5, 2026

Last Update Submitted That Met QC Criteria

March 4, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SNUH-ICARIIN

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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