Table 5. Crow’s-feet visual scores and skin roughness parameters.

Parameters		CTP20 group		Placebo group		CTP20/Placebo
		Mean ± SD	P-valuea	Mean ± SD	P-valuea	P-valueb
Crow's-feet visual grade
	Baseline	2.585 ± 0.706		2.946 ± 0.970
	At 6 weeks	2.500 ± 0.750	0.070	2.919 ± 0.954	0.480	0.312
	At 12 weeks	2.293 ± 0.741	< 0.001***	2.919 ± 0.932	0.581	0.004††
Wrinkle by Ra (Arithmetic average roughness, μm)
	Baseline	12.905 ± 2.448		12.845 ± 2.509
	At 6 weeks	12.650 ± 2.471	< 0.001***	12.835 ± 2.501	0.635	0.005††
	At 12 weeks	12.404 ± 2.149	< 0.001***	12.789 ± 2.404	0.556	< 0.001†††
Wrinkle by Rq (Root mean square roughness, μm)
	Baseline	15.867 ± 2.971		15.823 ± 3.072
	At 6 weeks	15.592 ± 3.010	< 0.001***	15.829 ± 3.117	0.757	0.012†
	At 12 weeks	15.312 ± 2.638	< 0.001***	15.784 ± 2.957	0.803	0.001††
Wrinkle by Rmax (Maximum roughness depth, μm)
	Baseline	84.204 ± 16.824		84.140 ± 16.181
	At 6 weeks	83.653 ± 17.914	0.499	83.888 ± 17.442	0.582	0.822
	At 12 weeks	82.399 ± 16.518	0.046*	84.409 ± 16.341	0.531	0.045†

Hydrolyzed fish collagen (Collagen-Tripep20™, Tripep20) was prepared from Pangasius hypophthalmus fish skin by collagenase digestion. Liquid collagen (1,000 mg Tripep20) or placebo in a 50 mL bottle was administered orally to all subjects as a daily drink. The crow’s-feet visual scores were analyzed by dermatologists, and the skin roughness parameters were measured using a PRIMOS High Resolution.

^aP-value for the Wilcoxon signed-rank test, compared to the baseline.

^bP-value for the Mann-Whitney U test using delta values, comparing values between the Tripep20 and the placebo.

^*P < 0.05, ^***P < 0.001 (Wilcoxon signed-rank test); ^†P < 0.05, ^††P < 0.01, ^†††P < 0.001 (Mann-Whitney U test using delta values).