The researchers also reported seeing the strongest effects when the two routes were combined.
Researchers at Kaohsiung Medical University and Chia Nan University of Pharmacy and Science conducted the randomised, double-blind, placebo-controlled trial.
The results positioned ACS as a candidate active for cosmeceuticals and nutricosmetics targeting brightness, texture, hydration, and collagen support in healthy adults.
The study enrolled 150 healthy adults aged 20 and above. Around 30% were aged 20 to 40, while 70% were over 40, creating a population relevant for anti-ageing and skin maintenance claims.
The participants were divided into six arms of 25 each, with a female-dominant profile typical of skin trials.
The study compared a 5% ACS cream, ACS capsules (125mg proprietary extract, taken twice daily), as well as a combination of both formats, against matching placebo cream and capsules. The topical-only group used the cream for four weeks, while the oral and combination groups continued for 12 weeks.
Topical ACS improved brightness, pores and texture
After four weeks of twice-daily facial application, the ACS cream group showed significant changes in key biophysical parameters compared with baseline, and outperformed placebo on several readouts.
Skin brightness (L value) increased by 2.5% in the ACS group, versus 1% in the placebo group.
Elasticity rose by 6.5% with ACS, compared to 1.2% with placebo, indicating firmer and more resilient skin. Collagen content increased by 8.7% in the ACS group, versus 6.8% for placebo; both changes were statistically significant, but the ACS effect was more pronounced.
Pigmentation indices also shifted. Melanin values fell by 5.2% with ACS, while the placebo group showed a slight increase of 0.2%, supporting a potential skin-brightening or tone-evening claim.
Visible pore count dropped by 10.6% with ACS compared with only 0.9% in the placebo group, and texture scores improved by 8.7% in the ACS group versus 2.3% with placebo.
Moisture increased by 7.6% in the ACS group and 1.8% in the placebo arm, though this difference did not reach statistical significance. Still, the four-week intervention delivered clinically visible changes in luminosity, pore appearance, and surface smoothness.
Oral ACS supported collagen and texture
Oral supplementation with ACS capsules for 12 weeks provided a complementary pattern of benefits. Participants taking ACS showed a 2.5% increase in skin brightness and a 4.7% improvement in elasticity versus their own baselines. Collagen content rose by 13.2%, indicating changes deeper in the skin structure.
Melanin values declined by 6.3%, suggesting better control of pigmentation and potential support in hyperpigmentation-prone profiles.
The most striking effect was on texture — surface roughness decreased by 18.5%, pointing to smoother skin with fewer visible fine lines and irregularities.
Pore count fell by 10.5%, although this change did not reach statistical significance.
The placebo capsule group showed no meaningful improvement and even trended down in several measures, with small reductions in moisture, elasticity, and collagen — consistent with natural skin ageing and seasonal variation.
The authors proposed that ACS’s active compounds were absorbed in the gut and reached the skin via the bloodstream, where they may have stimulated fibroblasts, enhanced collagen and hyaluronic acid production, and improved antioxidant defences.
This data supports ACS as a stand-alone nutricosmetic active or part of a broader anti-ageing blend.
Combined approach delivered strongest outcomes
The most compelling data came from the 12-week combination group, which used both ACS cream and capsules. This dual-route strategy produced broad and additive effects across all measured endpoints.
Brightness increased by 4.2%, a higher gain than in either the topical-only or oral-only groups. Moisture rose by 12.9%, indicating a stronger barrier and improved water-holding capacity. Elasticity improved by 9.0%, and collagen content increased by 13.7%.
Pigmentation markers also responded. Melanin values fell by 8.2%, while visible pores dropped by 28.5%, the largest reduction observed in the trial. Texture improved by 19.8%, confirming a smoother, more refined skin surface.
In contrast, the combination placebo group showed only modest shifts, such as a 2.6% increase in elasticity and 7.9% rise in collagen, with no significant change in brightness, moisture, melanin or texture.
Statistical comparisons showed that the ACS combination significantly outperformed placebo for brightness, moisture, melanin reduction, pore count, and texture.
Study limits and future implications
The trial strengthens the evidence base for A. membranaceus and C. asiatica as dual-use botanicals in dermocosmetic and supplement formats. It also fits the market shift towards plant-based, clinically supported actives that can underpin premium claims.
However, the authors highlighted limitations. Each group contained only 25 participants, the cohort was predominantly female, and the study did not stratify outcomes by age. The trial also focused on healthy adults rather than patients with defined skin conditions.
Larger, longer-term studies and age-specific analyses would help refine target consumer groups and support stronger structure-function or cosmetic claims.
The authors concluded: “The results of this study suggest that ACS exerts its skin rejuvenating effects through multiple biological mechanisms. This highlights ACS as a versatile and efficacious agent capable of addressing both superficial and structural signs of skin ageing. Taken together, ACS represents a promising natural solution for individuals seeking a holistic, evidence-based strategy to support and enhance skin health.
“Its demonstrated efficacy through both topical and oral routes of administration makes it particularly well suited for incorporation into cosmeceutical formulations and functional health supplements. Future research may further explore its applications in broader populations or in combination with other synergistic bioactives, thereby expanding its clinical relevance and commercial potential.”
Source: Cosmetics
“Natural Plant-Based Rejuvenating Compositions: Human Study on Astragalus membranaceus and Centella asiatica Saponins for Skin Health”
https://doi.org/10.3390/cosmetics12040131
Authors: Leong-Perng Chan, et al.
