Do Collagen Supplements Actually Work? A Dermatologist Reviews the Evidence.
Collagen supplements are a billion-dollar industry built on a simple promise: eat collagen, get better skin. Dr. Dray, a board-certified dermatologist known for her no-nonsense approach to skincare science, sits down for 12 minutes to evaluate whether that promise holds up. The answer, as usual in medicine, is complicated.
What Collagen Actually Is
Collagen is the most abundant protein in your body. It is the structural scaffolding of your skin, tendons, ligaments, bones, and gut lining. Think of it as the rebar inside concrete. Without it, things fall apart. Your body makes collagen constantly, but production starts declining around age 25. By the time you hit 60, you are making roughly half of what you produced at your peak.
This decline shows up as wrinkles, sagging skin, joint stiffness, and slower wound healing. It is also relevant to anyone on a GLP-1 medication experiencing skin changes from rapid weight loss. Your skin needs collagen to maintain its structure, and if production is already declining with age, the added stress of rapid body composition changes can make things worse.
Types of Collagen Supplements
Dr. Dray breaks down the three main forms you will encounter.
Gelatin is collagen that has been partially broken down by heat. It is what makes Jell-O gel. When you drink bone broth for the collagen benefits, you are mainly getting gelatin. The molecules are large and the absorption question is real.
Hydrolyzed collagen, also called collagen peptides, is gelatin that has been broken down further into smaller fragments. These are the pills and powders you see at every supplement store. The smaller peptide size means better absorption through the gut lining. Most clinical studies use this form.
Then there is undenatured type II collagen, which is a different approach entirely. Rather than providing building blocks, it is supposed to work through immune modulation, training your immune system not to attack your own cartilage. This form is mainly studied for joint health, not skin.
What the Studies Actually Show
Dr. Dray is known for reading the actual papers, more than the abstracts. Here is what she found.
For skin, there are several randomized controlled trials showing that hydrolyzed collagen supplements (typically 2.5 to 10 grams daily) improve skin elasticity, hydration, and wrinkle depth over 8 to 12 weeks. The effects are modest but measurable. One study she references showed a 20% improvement in skin elasticity after 8 weeks of supplementation.
She is quick to point out the limitations. Many of these studies are funded by supplement companies. Sample sizes tend to be small. And the improvements, while statistically significant, are not dramatic. You are not going to reverse 20 years of aging with a collagen powder.
For joints, the evidence is a bit stronger. Several studies have shown reductions in joint pain and improved mobility in people with osteoarthritis taking 10 grams of hydrolyzed collagen daily. The mechanism likely involves providing amino acids specifically needed for cartilage repair.
The Absorption Question
This is where the skeptics push back, and Dr. Dray addresses it head-on. The argument goes like this: when you eat collagen, your digestive system breaks it down into individual amino acids. So you are not absorbing collagen. You are absorbing glycine, proline, and hydroxyproline. Your body then uses those amino acids however it sees fit, not necessarily to make new collagen.
Dr. Dray says this argument is partially correct but incomplete. Research has shown that some collagen peptides survive digestion intact and can be detected in the bloodstream. These small peptides may act as signaling molecules, telling fibroblasts in the skin to ramp up collagen production. It is about more than raw materials. It may also be about sending a biological signal.
This is an evolving area of research. The signaling hypothesis is supported by some cell culture and animal studies but needs more human validation. Dr. Dray presents it fairly without overselling it.
Who Might Actually Benefit
Dr. Dray identifies several groups where the evidence is most supportive.
People over 40 with noticeable skin aging. The decline in natural collagen production means external supplementation has the most room to make a difference.
People with joint pain or early osteoarthritis. The joint health data is genuinely encouraging, especially at higher doses.
People experiencing rapid weight loss, whether from GLP-1 medications, bariatric surgery, or significant lifestyle changes. When your body is under stress from major composition changes, providing extra collagen building blocks is a reasonable strategy even if the evidence is not bulletproof.
Athletes or people with high training loads. The mechanical stress on tendons and ligaments creates a higher demand for collagen synthesis.
What She Does Not Recommend
Dr. Dray is skeptical of bone broth as a meaningful collagen source. The amount of collagen in a typical serving of bone broth is much lower than what is used in studies. You would need to drink several cups daily to match the doses that showed benefits in trials.
She also pushes back on the idea that collagen supplements replace good skincare. Sunscreen, retinoids, and vitamin C are still the foundation. Collagen supplements might add a small incremental benefit on top of an already solid routine. They are not a substitute for the basics.
How to Choose a Collagen Product (If You Decide to Try One)
Dr. Dray touches on this briefly, but the supplement market is confusing enough to warrant more detail. Not all collagen supplements are created equal. Look for products that specify hydrolyzed collagen peptides rather than just "collagen." Check for third-party testing from organizations like NSF International, USP, or Informed Sport. These certifications mean the product has been independently verified for purity, potency, and the absence of contaminants like heavy metals. The source of collagen matters less than the processing. Bovine (cow), marine (fish), and porcine (pig) collagen all provide similar amino acid profiles once hydrolyzed. Marine collagen peptides tend to have smaller molecular weight, which may improve absorption, but the clinical difference is not well established. Avoid products with long ingredient lists that include added sugars, fillers, or unnecessary vitamins. You want collagen peptides, not a collagen-flavored multivitamin. And be wary of products that cost dramatically less than competitors. Cheap collagen often means lower-quality sourcing and processing.
What the Video Gets Right and What It Leaves Out
Dr. Dray does an excellent job presenting the clinical evidence fairly. She does not oversell collagen supplements, and she does not dismiss them. Her summary of the randomized controlled trials is accurate, and her point about the signaling hypothesis (that collagen peptides may trigger fibroblast activity rather than just providing raw materials) is genuinely interesting science that most supplement marketing ignores.
What the video leaves out is the connection between collagen supplementation and other interventions that affect the same systems. For example, BPC-157, one of the most discussed peptides in the FormBlends library, has shown effects on tissue repair and gut healing that overlap with some of the benefits people seek from collagen supplements. The mechanisms are different, but the target outcomes are related. Someone dealing with gut permeability issues might benefit from both collagen peptides for structural support and BPC-157 for its anti-inflammatory and healing signaling effects. Dr. Dray stays in her lane as a dermatologist, which is appropriate, but viewers interested in the broader tissue repair picture should watch the Huberman peptide therapeutics episode and the Dr. Edwin Lee episode on FormBlends for a more complete view.
She also does not address the timing of collagen intake relative to exercise, which is an emerging area of research. A 2017 study in the American Journal of Clinical Nutrition found that taking 15 grams of gelatin (a collagen source) with vitamin C 60 minutes before exercise increased collagen synthesis markers in engineered ligaments. The idea is that exercise-induced blood flow to tendons and ligaments, combined with available collagen building blocks, creates a window of enhanced repair. This is speculative but grounded in real physiology, and it costs nothing to time your collagen supplement before a workout rather than at a random time of day.
Collagen and GLP-1 Medications: A Specific Connection
Dr. Dray mentions rapid weight loss as a scenario where collagen supplementation might be particularly useful, but she does not connect this specifically to GLP-1 drugs. That connection deserves more attention because it is directly relevant to a huge number of people right now.
GLP-1 medications like semaglutide and tirzepatide suppress appetite so effectively that many patients eat dramatically less protein than they need. Protein is the raw material for collagen synthesis. If you are eating 800-1,000 calories a day because you are simply not hungry, you are almost certainly not getting enough protein to maintain your skin, tendons, joints, and gut lining. Add the mechanical stress of rapid weight loss on your skin (the Ozempic Butt video with Dr. Portela covers this in detail), and you have a situation where collagen demand is going up while collagen supply is going down.
This is where targeted collagen supplementation makes the most sense. Adding 10-15 grams of hydrolyzed collagen peptides daily provides glycine, proline, and hydroxyproline without requiring you to eat a large amount of food. It is an efficient way to support collagen synthesis when your total calorie intake is restricted. Combine it with 500-1,000mg of vitamin C to support the enzymatic conversion, and you are covering the nutritional bases for collagen production even on a reduced-calorie diet.
The Cost-Benefit Math on Collagen Supplements
Collagen supplements are not free, and the effects are modest, so the value question is fair. A quality hydrolyzed collagen powder from a third-party tested brand runs about $25-40 per month at a 10-gram daily dose. Over a year, that is $300-480. Is that worth a 20% improvement in skin elasticity and some reduction in joint discomfort?
That depends on your situation. For a 55-year-old on a GLP-1 medication who is losing weight rapidly and worried about skin laxity, the downside risk of collagen supplementation is essentially zero (no meaningful adverse effects in the clinical literature) and the potential benefit is directly relevant. At $30 per month, it is one of the cheapest interventions available for that specific concern. Compare that to a single Morpheus8 skin tightening session at $1,500-3,000 or body contouring surgery at $10,000+.
For a healthy 30-year-old with good skin and no joint issues, the value proposition is much weaker. The baseline collagen production is still high, the clinical improvements are modest, and the money might be better spent on creatine, omega-3s, or other supplements with stronger evidence for their age group. Dr. Rhonda Patrick's episode on Huberman Lab (also on FormBlends) provides a good framework for prioritizing supplements based on evidence strength.
A Note on Collagen for Gut Health
One application of collagen that Dr. Dray does not cover, since it falls outside dermatology, is gut health. Glycine, the most abundant amino acid in collagen, plays a role in maintaining the gut lining. Some practitioners recommend collagen supplements or bone broth for patients with increased intestinal permeability (sometimes called "leaky gut"), and there is limited but suggestive evidence that glycine-rich proteins support gut barrier function.
This matters for GLP-1 users because these drugs can cause gastrointestinal side effects including nausea, constipation, and diarrhea. Supporting gut lining integrity through collagen supplementation is a low-risk strategy that some gastroenterologists recommend alongside GLP-1 therapy. It is not a proven treatment for GI side effects, but the biological rationale is reasonable, and the safety profile is clean. For a more targeted gut health approach, the BPC-157 content elsewhere in the FormBlends library covers a peptide with stronger (though still mostly animal-based) evidence for gut healing.
The Practical Takeaway
If you decide to try collagen, Dr. Dray suggests hydrolyzed collagen peptides at 5-10 grams daily. Look for third-party tested products. Give it at least 8-12 weeks before judging results. And keep your expectations realistic. This is a modest intervention with modest effects, not a miracle supplement. But for the right person at the right time, the evidence suggests it is worth trying.