This randomized, double-blind, monocentric, five-way cross-over study aims to collect human serum and plasma samples at 1 and 2 hours after ingestion of hydrolyzed collagen peptides. The enriched sera will be used for ex vivo/ in vitro experiments on skin keratinocytes, fibroblasts, and other cell types to explore the beneficial effects of bioactive collagen peptides. Blood will also be analyzed for amino acid profiles and collagen-derived peptides.

Inclusion Criteria:

• Participant is able and willing to sign the Informed Consent Form prior to screening evaluations
• Age: 35 - 45 years
• Women
• BMI: 19 - 25 kg/m2
• Non-smoker
• Participant is in good physical and mental health as established by medical history, physical examination, electrocardiogram, vital signs, results of biochemistry and haematology at screening

Exclusion Criteria:

• Relevant history or presence of any severe medical disorder, potentially interfering with this study (e.g. mal absorption, chronic gastro-intestinal diseases, heavy depression, diabetes, significant CVD events, acute cancers within last 3 years except basal cell carcinoma of the skin, etc.)
• Significant changes in lifestyle or medication (within last 3 mo.) or surgical intervention or surgical procedure such as bariatric surgery
• Application of corticoids (intravenously, orally or intraarticularly) and other immune-suppressing drug (within last 2 weeks)
• Blood donation within 1 month prior to study start or during study
• Low haemoglobin levels < 12 g/dL
• Regular intake of drugs or supplements possibly interfering with this study within 2 weeks prior to study start or during study (stable medication since > 3 months e.g. L-Thyroxin, blood pressure medication etc. allowed)
• Chronic intake of substances affecting blood coagulation (e.g. acetylic acid, anticoagulants (e.g. Marcumar), diuretics, thiazides), which in the investigator's opinion would impact participant safety
• Not willing to avoid intake of pain relievers e.g. Paracetamol or Ibuprofen 24h prior to study days
• Participants with history of drug, alcohol or other substance abuse, or other factors limiting their ability to co-operate during the study
• History of hypersensitivity to fish
• HIV-infection, acute or chronic hepatitis B and C infection
• Known pregnancy, breast feeding or intention to become pregnant during the study. A pregnancy test will be conducted during screening and visits 1-5.
• Participation in another clinical study within the last 4 weeks and concurrent participation in another clinical study
• Anticipating any planned changes in lifestyle for the duration of the study
• Participants considered inappropriate for the study by investigators, including participants who are unable or unwilling to show compliance with the protocol