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

Exclusion Criteria

• •Pregnancy or breastfeeding.
• •Vegan diet.
• •Heavy smoking or frequent alcohol-induced flushing.
• •Occupational or hobby-related excessive heat exposure (e.g. chefs, sauna workers) likely to interfere with vascular stability.
• •Anticipated sunbathing or solarium use, or major planned changes in sun exposure before or during the study.
• •Planned major changes during the study in:
• •* Skincare routine
• •* Hormonal therapy (contraception or hormone replacement therapy)
• •Significant changes in dietary habits or dietary supplementation within 3 months prior to inclusion.
• •Regular use within 3 months prior to inclusion of food supplements containing:
• •* Methylsulfonylmethane (MSM);
• •* Collagen or other protein-based supplements;
• •* Anti-inflammatory supplements (e.g. bioflavonoids/rutin, curcumin, EPA) and/or antioxidant supplements with a known or potential impact on skin inflammation or vascular response.
• •Any diagnosed, uncontrolled, untreated, or unstable medical condition.
• •Clinically significant history of metabolic, gastrointestinal, hepatic, renal, or haematological disease.
• •Mental incapacity or psychiatric condition that may impair understanding of the study or compliance with study requirements.
• •Any clinically significant acute or chronic inflammatory skin disease, including but not limited to acne, perioral dermatitis, psoriasis, atopic dermatitis, or lupus.
• •Skin pigmentation disorders at the assessment sites.
• •Active rosacea within 3 months prior to study entry, defined as the presence of papules/pustules, frequent flushing episodes typical of rosacea, or ocular involvement.
• •Frequent vasomotor hot flushes (e.g. perimenopausal or menopausal), which may interfere with erythema assessments.
• •Use of medications affecting skin or vascular reactivity, including but not limited to: systemic corticosteroids, anticoagulants (e.g. coumarins, heparin), vasodilators (e.g. hydralazine, nitroglycerin), antibiotics with potential to affect erythema or vascular response, immunomodulators, regular or long-term use of non-steroidal anti-inflammatory drugs (NSAIDs)
• •Use of systemic retinoids within 3 months prior to study entry.
• •Changes of skin care routine regimen within 4 weeks prior to study entry.
• •Use of highly concentrated topical products (\>15% azelaic acid, 10% vitamin C…) affecting inflammatory or vascular facial responses within 4 weeks prior to study entry.
• •Invasive rejuvenation treatments (e.g. medium or deep chemical peels, ablative or vascular laser therapies) within 6 months prior to study entry.
• •Non-invasive or minimally invasive rejuvenation treatments (e.g. microneedling, mesotherapy, superficial chemical peels, radiofrequency, electrotherapy, ultrasound, IPL) within 3 months prior to study entry.
• •Known or suspected allergy to any ingredient of the investigational product(s).