The Effect of 16-week Dietary Intake of Food Supplements Containing Collagen and MSM on Facial Erythema and Other Skin Parameters

Inclusion criteria: * Caucasian female volunteers aged 35 to 65 years at the time of signing the Informed Consent Form (ICF). * Signed Informed Consent Form (ICF). * Fitzpatrick skin phototypes I-IV. * Presence of visible signs of skin ageing. * Presence of visible facial telangiectasias, primarily on the cheeks. * Presence of facial erythema with a baseline score ≤ 3 on the 5-point Clinical Erythema Assessment (CEA) scale. * Stable erythema-prone facial skin for at least 3 months prior to study inclusion, without clinical signs of active rosacea. * In good general health, as determined by medical history. * Body Mass Index (BMI) \< 35. * Willingness and ability to: * Comply with all study procedures and complete a subject diary. * Maintain usual lifestyle habits throughout the study. * Not initiate or modify oestrogen or progesterone therapies during the study. * Maintain the same cosmetic and skincare routine and comply with sun protection guidelines throughout the study. * Avoid rejuvenation treatments during the study. * Refrain from consuming food supplements containing collagen or other protein-based supplements, methylsulfonylmethane (MSM), or anti-inflammatory and/or antioxidant compounds with a known or potential impact on skin inflammation or vascular response for the duration of the study. Exclusion criteria: * Pregnancy or breastfeeding. * Vegan diet. * Heavy smoking or frequent alcohol-induced flushing. * Occupational or hobby-related excessive he…