Targeting Circadian Rhythm for the Regulation of Skin Collagen Metabolism.

Wang C, Song T, Zhang Y, Li N, Xie L, Xie M, Jiang X, Lü G, Meng Y, Wang C, Yue L, Yang W, Li Y, Wu Y, Chen L

Journal of cosmetic dermatology1 Jan 2026Cited by 1 (Europe PMC)

PMID41527525PMCIDPMC12797011DOI10.1111/jocd.70638PepBankPUB-41527525

Summary

BackgroundCollagen is essential for maintaining skin structure and function, and the circadian rhythm is known to regulate a wide range of physiological processes.AimsTo investigate whether collagen metabolism in human skin fibroblasts exhibits circadian regulation, and to evaluate whether the time-coordinated application of baicalin at daytime and palmitoyl tripeptide-1 (PT-1) at nighttime synergistically promotes collagen fiber formation and improves overall skin quality.MethodsA circadian-synchronized human skin fibroblast model was established. The expression of collagen metabolism-related genes was analyzed using qPCR and immunofluorescence. Subsequently, an 8-week topical application study was conducted in mice using a regimen of daytime baicalin and nighttime PT-1. Finally, a clinical trial involving 30 female participants was conducted, employing the same time-coordinated application scheme.ResultsFibroblasts exhibited opposing day-night rhythms: genes for collagen assembly (e.g., LOX) peaked during the day, while those involved in synthesis/secretion (e.g., Sec61a2, Mia3, Pde4d, Vps33b) and degradation (e.g., CTSK, MMP1) peaked at night. Time phase-dependent interventions showed baicalin enhanced daytime assembly, while PT-1 boosted nighttime synthesis. In mice, a timed day-night combination therapy increased collagen fiber density. Clinical trial (n = 30) confirmed the efficacy, showing significant improvements in skin luminance (+16.29%), nasolabial fold depth (-36.35%), and firmness (R2: +24.35%).ConclusionsCollagen metabolism is regulated by circadian rhythms. Chronomodulated baicalin and PT-1 application synergistically optimize collagen metabolism and improve skin quality.

CC BYText from Europe PMC. Highlighted sentences are the source of results.

Results from this study5

1 result from studies that gave the peptide. No result from this study comes from people.

01LabIn vitro (cells)Efficacy outcome
In human skin fibroblasts, PT-1 boosted nighttime collagen synthesis.
In plain wordsIn cells, PT-1 increased nighttime collagen production.
Peptide
Palmitoyl tripeptide-1
Outcome
IncreaseNighttime collagen synthesis
Study
humann: not reported in source
circadian-synchronized skin fibroblasts
Outcome group
Skin and hair · Skin and wound
Studied dose
Dose not stated
Source sentences
Summary
Time phase-dependent interventions showed baicalin enhanced daytime assembly, while PT-1 boosted nighttime synthesis.
1 context sentence(design, population, supporting numbers)
Summary · context
A circadian-synchronized human skin fibroblast model was established.
Show in the study text Report a problemFND-4152752501

Studies that did not test the peptide alone4

In this study, Palmitoyl tripeptide-1 was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking Palmitoyl tripeptide-1.

02HumanNot a test of Palmitoyl tripeptide-1 aloneNon-randomized trialEfficacy outcome
In women, timed baicalin and PT-1 improved skin luminance by +16.29%.
In plain wordsIn women, the timed baicalin and PT-1 combination improved skin brightness.
Peptide
Palmitoyl tripeptide-1
Outcome
IncreaseSkin luminance
Study
n = 30
Outcome group
Skin and hair · Skin and wound
Measurements
Skin luminance improvement
16.29%
timed baicalin daytime and PT-1 nighttime regimen
Source sentences
Summary
Clinical trial (n = 30) confirmed the efficacy, showing significant improvements in skin luminance (+16.29%), nasolabial fold depth (-36.35%), and firmness (R2: +24.35%).
1 context sentence(design, population, supporting numbers)
Summary · context
Finally, a clinical trial involving 30 female participants was conducted, employing the same time-coordinated application scheme.
In this study, Palmitoyl tripeptide-1 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Palmitoyl tripeptide-1.
Show in the study text Report a problemFND-4152752503
03HumanNot a test of Palmitoyl tripeptide-1 aloneNon-randomized trialEfficacy outcome
In women, timed baicalin and PT-1 reduced nasolabial fold depth by 36.35%.
In plain wordsIn women, the timed baicalin and PT-1 combination reduced nasolabial fold depth.
Peptide
Palmitoyl tripeptide-1
Outcome
DecreaseNasolabial fold depth
Study
n = 30
Outcome group
Skin and hair · Skin and wound
Measurements
Change in nasolabial fold depth
−36.35%
30 women, timed baicalin and PT-1 regimen
Source sentences
Summary
Clinical trial (n = 30) confirmed the efficacy, showing significant improvements in skin luminance (+16.29%), nasolabial fold depth (-36.35%), and firmness (R2: +24.35%).
1 context sentence(design, population, supporting numbers)
Summary · context
Finally, a clinical trial involving 30 female participants was conducted, employing the same time-coordinated application scheme.
In this study, Palmitoyl tripeptide-1 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Palmitoyl tripeptide-1.
Show in the study text Report a problemFND-4152752504
04HumanNot a test of Palmitoyl tripeptide-1 aloneNon-randomized trialEfficacy outcome
In women, timed baicalin and PT-1 improved firmness (R2: +24.35%).
In plain wordsIn women, the timed baicalin and PT-1 combination improved skin firmness.
Peptide
Palmitoyl tripeptide-1
Outcome
IncreaseSkin firmness
Study
n = 30
Outcome group
Skin and hair · Skin and wound
Measurements
Change in skin firmness (R2)
24.35%
30 women, timed baicalin and PT-1 regimen
Source sentences
Summary
Clinical trial (n = 30) confirmed the efficacy, showing significant improvements in skin luminance (+16.29%), nasolabial fold depth (-36.35%), and firmness (R2: +24.35%).
1 context sentence(design, population, supporting numbers)
Summary · context
Finally, a clinical trial involving 30 female participants was conducted, employing the same time-coordinated application scheme.
In this study, Palmitoyl tripeptide-1 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Palmitoyl tripeptide-1.
Show in the study text Report a problemFND-4152752505
05AnimalNot a test of Palmitoyl tripeptide-1 aloneAnimal study (in vivo)Efficacy outcome
In mice, timed daytime baicalin and nighttime PT-1 increased collagen fiber density.
In plain wordsIn mice, the timed baicalin and PT-1 combination increased collagen fiber density.
Peptide
Palmitoyl tripeptide-1
Outcome
IncreaseCollagen fiber density
Study
mousen: not reported in source
topical day-night regimen
Outcome group
Skin and hair · Skin and wound
Source sentences
Summary
In mice, a timed day-night combination therapy increased collagen fiber density.
1 context sentence(design, population, supporting numbers)
Summary · context
Subsequently, an 8-week topical application study was conducted in mice using a regimen of daytime baicalin and nighttime PT-1.
In this study, Palmitoyl tripeptide-1 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Palmitoyl tripeptide-1.
Show in the study text Report a problemFND-4152752502

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
27 Oct 2026, 18:20 UTC
Study results updated
Version 1
27 Oct 2026, 16:32 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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