How much collagen per day is worthwhile?
For the skin, 2.5 to 5 grams of hydrolysed collagen per day demonstrably works after at least 8 to 12 weeks: pay attention to the active peptide content, not just the grams on the label. For knee complaints, a completely different product has been studied, so look carefully at which form you buy.
For the skin, the form that works is hydrolysed collagen. On the label this appears as 'collagen peptides', 'hydrolysed collagen' or 'collagen hydrolysate'. Whether it comes from fish, beef or pork makes no difference. Take 2.5 to 5 grams per day for at least 8 to 12 weeks. Several studies and two meta-analyses show measurable improvements in skin moisture, elasticity and wrinkles after that period.
The grams on the label are not the whole story. One study compared two products of equal weight but with different concentrations of active peptides: the product with more active peptides produced clearly greater improvements in moisture, elasticity and wrinkles. Quality therefore matters at least as much as quantity. Adding hyaluronic acid to the formula offered no extra benefit over collagen with vitamin C alone, according to a study of 87 women. Combining vitamin C is worthwhile, though: your skin's own collagen production depends on vitamin C. In that study, dermal density, texture and wrinkle visibility all improved after 16 weeks in women aged 40 to 65.
For knee pain caused by osteoarthritis, entirely different rules apply. Here you can try two distinct products. The first is unprocessed type II collagen, labelled 'UC-II' or 'undenatured type II collagen', in a capsule of 40 mg per day for 6 months. A study of 191 participants found this performed better than a placebo and better than glucosamine plus chondroitin, though that study was conducted by employees of the manufacturer. The second is ordinary hydrolysed collagen (collagen peptides) as a powder, 10 grams per day for 6 months. These are fundamentally different products from the 2.5 to 5 grams used for the skin: they cannot be used interchangeably.
For hair, nails, tendons or muscle mass, collagen has been too little studied to recommend. Do not buy it for those purposes. No side effects were reported in any of the studies. Most studies lasted no longer than three to six months, so very little is known about longer-term effects.
This answer is based on eight randomised studies and one systematic review of eleven such studies. The systematic review included a total of 805 participants. One of the review articles used was written by authors affiliated with a collagen manufacturer, which may introduce bias in that source; the remaining studies are of a more independent design. Most studies lasted eight to sixteen weeks and examined middle-aged women; whether the effects also apply to men or younger people cannot be determined from these studies.
Does collagen help women over fifty?
For skin, collagen is reasonably well supported in women over fifty: 2.5 to 5 grams per day for 8 to 12 weeks measurably improves elasticity and wrinkles. For bone density after menopause there are positive indications, but discuss that with your doctor first.
Do collagen supplements work against skin ageing?
Collagen supplements show positive effects in many studies, but those effects come almost entirely from manufacturer-funded research. Independent evidence is still lacking, so it is wise to keep expectations in check until more independent research becomes available.
Does taking collagen really work against wrinkles?
Collagen supplements show positive effects on wrinkles and skin hydration in many studies, though most of those studies were funded by the industry.
How much sun is safe, and does the tanning bed really cause skin cancer?
Tanning beds genuinely cause skin cancer: the evidence is causal and strong. Short, regular sun exposure is beneficial for vitamin D, but burning must be avoided at all times.
Which type of collagen is best to take?
For the skin, hydrolysed collagen peptides (2.5 to 5 grams per day for at least 8 to 12 weeks) are the best-supported option. For knee pain, you can try UC-II (40 mg per day) or hydrolysed collagen (10 grams per day) for six months, but the only independent study found no effect.
Does collagen help your joints and your skin?
For joint pain due to knee osteoarthritis and for active athletes, collagen is worth trying: 10 grams of collagen peptides per day for 6 months, preferably in combination with exercise. For the skin, 2.5 to 5 grams per day is recommended, but some of the research comes from manufacturers.