Hydrolyzed collagen peptides do reach the bloodstream and dermis as di- and tripeptides. But the strongest clinical evidence comes from industry-funded studies — independent research is far less convincing. Photo: SWinxy / Wikimedia Commons / CC BY 4.0 Why Does Jennie Drink Chicken Feet Soup? In multiple interviews, BLACKPINK's Jennie has shared that she starts her mornings with chicken feet collagen soup — a traditional Korean broth simmered from chicken feet, which are almost entirely composed of skin, cartilage, and connective tissue. In Korea, this isn't unusual. 닭발 국물 (dakbal gungmul) has been a beauty food staple for decades, long before collagen supplements became a global wellness trend. The logic is simple: chicken feet are roughly 70% collagen by dry weight. Boil them long enough, and you extract gelatin — a partially hydrolyzed form of collagen — into the broth. But here's the question everyone asking: does that collagen actually survive digestion, enter the bloodstream, and make it to your skin? Or does your stomach just break it down into generic amino acids like any other protein? Does Oral Collagen Actually Get Absorbed Into the Skin? Yes — but the form matters enormously. Native collagen molecules are far too large to survive digestion intact. They're triple-helix proteins with molecular weights around 300,000 daltons. Your stomach acid and digestive enzymes break them into fragments. The question is what size those fragments are when they reach your bloodstream. Gelatin (what you get from bone broth or chicken feet soup) has a molecular weight of ~20,000–100,000 daltons. Hydrolyzed collagen peptides in supplements are pre-broken to ~2,000–5,000 daltons. A clinical study found that free hydroxyproline absorption from gelatin (94.4 nmol/mL) was significantly lower than from hydrolyzed collagen (169.1 nmol/mL). Translation: supplements are roughly twice as bioavailable as Jennie's soup. Gelatin vs. Hydrolyzed Peptides A 2024 randomized crossover study confirmed that hydrolyzed collagen peptides — regardless of source (fish, porcine, bovine) — are absorbed as di- and tripeptides like Gly-Pro-Hyp and Pro-Hyp. These specific peptides have been detected in human skin tissue, meaning they do travel from your gut to your dermis. Once there, they appear to stimulate fibroblasts to produce new type I and III collagen. What Did the 2025 Meta-Analysis Actually Find? This is where it gets uncomfortable for the collagen industry. A 2025 meta-analysis in the American Journal of Medicine analyzed 23 randomized controlled trials with 1,474 participants. The headline finding: collagen supplements significantly improved skin hydration, elasticity, and wrinkles. But then the authors did something most meta-analyses don't: they separated the results by funding source. And the picture changed dramatically. Industry-funded studies Showed significant improvements in hydration, elasticity, and wrinkles. These are the results most brands cite in their marketing. Independent studies Showed no significant effect on hydration, elasticity, or wrinkles. When the money came from outside the collagen industry, the benefits disappeared. High-quality studies only Also showed no significant effect in any category. Low-quality studies drove the positive overall result. This doesn't prove collagen supplements don't work. It means we don't have strong independent evidence that they do. The mechanism is plausible — peptides do reach the skin — but the clinical proof of visible results is weaker than the $7 billion collagen industry suggests. What This Means Is Chicken Feet Soup Better Than Collagen Supplements? Probably not for collagen delivery specifically. Gelatin from broth has a higher molecular weight and lower bioavailability than hydrolyzed peptides. But chicken feet soup has things supplements don't: hyaluronic acid, glycosaminoglycans, and minerals from the cartilage — plus the hydration benefit of the broth itself. It's not an either-or choice. If you want maximum collagen bioavailability Go with hydrolyzed collagen peptides (2,000–5,000 daltons). Look for marine or bovine collagen with published absorption data. Take with vitamin C — it's a required cofactor for collagen synthesis. If you want the traditional approach Jennie's method isn't wrong — it's just less efficient for collagen delivery. Bone broth and chicken feet soup provide a broader nutrient profile. Simmer for 8+ hours to maximize gelatin extraction. If you're skeptical of both Focus on what definitely works: topical retinoids, vitamin C serums, and sunscreen protect existing collagen. Dietary protein from any source provides the amino acids your body needs. You don't specifically need collagen protein to make collagen. Which Collagen Products Are Worth Trying? If you want to try oral collagen, choose hydrolyzed peptides over gelatin, and marine collagen over bovine if you want the smallest molecular weight. Take with vitamin C. And manage expectations — the evidence is promising but not conclusive. Wild-caught fish collagen, low molecular weight. One of the few brands with published bioavailability data. Marine Collagen Peptides Korea's most-reviewed collagen powder on Naver. Fish collagen peptides with vitamin C built in. Absolute Collagen Powder If you'd rather go topical — this serum delivers collagen-boosting peptides directly to the skin, skipping the absorption question entirely. Revive Serum: Ginseng + Snail Mucin
Hydrolyzed collagen peptides do reach the bloodstream and dermis as di- and tripeptides. But the strongest clinical evidence comes from industry-funded studies — independent research is far less convincing. Photo: SWinxy / Wikimedia Commons / CC BY 4.0 Why Does Jennie Drink Chicken Feet Soup? In multiple interviews, BLACKPINK's Jennie has shared that she starts her mornings with chicken feet collagen soup — a traditional Korean broth simmered from chicken feet, which are almost entirely composed of skin, cartilage, and connective tissue. In Korea, this isn't unusual. 닭발 국물 (dakbal gungmul) has been a beauty food staple for decades, long before collagen supplements became a global wellness trend. The logic is simple: chicken feet are roughly 70% collagen by dry weight. Boil them long enough, and you extract gelatin — a partially hydrolyzed form of collagen — into the broth. But here's the question everyone asking: does that collagen actually survive digestion, enter the bloodstream, and make it to your skin? Or does your stomach just break it down into generic amino acids like any other protein? Does Oral Collagen Actually Get Absorbed Into the Skin? Yes — but the form matters enormously. Native collagen molecules are far too large to survive digestion intact. They're triple-helix proteins with molecular weights around 300,000 daltons. Your stomach acid and digestive enzymes break them into fragments. The question is what size those fragments are when they reach your bloodstream. Gelatin (what you get from bone broth or chicken feet soup) has a molecular weight of ~20,000–100,000 daltons. Hydrolyzed collagen peptides in supplements are pre-broken to ~2,000–5,000 daltons. A clinical study found that free hydroxyproline absorption from gelatin (94.4 nmol/mL) was significantly lower than from hydrolyzed collagen (169.1 nmol/mL). Translation: supplements are roughly twice as bioavailable as Jennie's soup. Gelatin vs. Hydrolyzed Peptides A 2024 randomized crossover study confirmed that hydrolyzed collagen peptides — regardless of source (fish, porcine, bovine) — are absorbed as di- and tripeptides like Gly-Pro-Hyp and Pro-Hyp. These specific peptides have been detected in human skin tissue, meaning they do travel from your gut to your dermis. Once there, they appear to stimulate fibroblasts to produce new type I and III collagen. What Did the 2025 Meta-Analysis Actually Find? This is where it gets uncomfortable for the collagen industry. A 2025 meta-analysis in the American Journal of Medicine analyzed 23 randomized controlled trials with 1,474 participants. The headline finding: collagen supplements significantly improved skin hydration, elasticity, and wrinkles. But then the authors did something most meta-analyses don't: they separated the results by funding source. And the picture changed dramatically. Industry-funded studies Showed significant improvements in hydration, elasticity, and wrinkles. These are the results most brands cite in their marketing. Independent studies Showed no significant effect on hydration, elasticity, or wrinkles. When the money came from outside the collagen industry, the benefits disappeared. High-quality studies only Also showed no significant effect in any category. Low-quality studies drove the positive overall result. This doesn't prove collagen supplements don't work. It means we don't have strong independent evidence that they do. The mechanism is plausible — peptides do reach the skin — but the clinical proof of visible results is weaker than the $7 billion collagen industry suggests. What This Means Is Chicken Feet Soup Better Than Collagen Supplements? Probably not for collagen delivery specifically. Gelatin from broth has a higher molecular weight and lower bioavailability than hydrolyzed peptides. But chicken feet soup has things supplements don't: hyaluronic acid, glycosaminoglycans, and minerals from the cartilage — plus the hydration benefit of the broth itself. It's not an either-or choice. If you want maximum collagen bioavailability Go with hydrolyzed collagen peptides (2,000–5,000 daltons). Look for marine or bovine collagen with published absorption data. Take with vitamin C — it's a required cofactor for collagen synthesis. If you want the traditional approach Jennie's method isn't wrong — it's just less efficient for collagen delivery. Bone broth and chicken feet soup provide a broader nutrient profile. Simmer for 8+ hours to maximize gelatin extraction. If you're skeptical of both Focus on what definitely works: topical retinoids, vitamin C serums, and sunscreen protect existing collagen. Dietary protein from any source provides the amino acids your body needs. You don't specifically need collagen protein to make collagen. Which Collagen Products Are Worth Trying? If you want to try oral collagen, choose hydrolyzed peptides over gelatin, and marine collagen over bovine if you want the smallest molecular weight. Take with vitamin C. And manage expectations — the evidence is promising but not conclusive. Wild-caught fish collagen, low molecular weight. One of the few brands with published bioavailability data. Marine Collagen Peptides Korea's most-reviewed collagen powder on Naver. Fish collagen peptides with vitamin C built in. Absolute Collagen Powder If you'd rather go topical — this serum delivers collagen-boosting peptides directly to the skin, skipping the absorption question entirely. Revive Serum: Ginseng + Snail Mucin