How to Choose a Collagen Powder: Bovine vs Marine, and What a Clean Label Means

For most people a hydrolysed grass-fed bovine collagen is the sensible choice, because type I and III collagen, the two kinds your body builds skin, hair, nails, joints, tendons and gut from, covers all of that in a single scoop. Marine collagen is type I only, with a skin focus and smaller peptides, but it comes from fish and can carry trace allergens. Beyond the type, two things matter more than the marketing on the front of the tub: a clean label with no fillers or sugar alcohols, and third-party testing for heavy metals, pesticides and glyphosate. Chief's unflavoured collagen is 100% hydrolysed grass-fed bovine collagen, tested for all three.

Start with skin, because that is what sends most people to collagen in the first place. The strongest evidence here is a 2021 review in the International Journal of Dermatology, which pooled 19 trials and around 1,125 people, mostly women, and found hydrolysed collagen improved skin hydration and elasticity against a placebo. That is a genuine result, but read the timeline hidden inside it. The studies that showed a change ran for about 8 to 12 weeks, so this is a habit you commit to, not a glow you see by Friday. Why it works at all comes down to raw material. Collagen is rich in glycine and proline, the amino acids your body uses to build skin, tendons, ligaments and the gut lining, so you are topping up the supply cupboard rather than buying a finished result off the shelf. One thing to be honest about before you go further: collagen is not a complete protein, and it will not replace whey when the goal is building muscle. Use it for the connective tissue, not as your main protein.

This is the fork in the road, and it is simpler than the shelf makes it look. Bovine collagen gives you type I and III, the pair that covers skin, hair, nails, joints, tendons and gut, which is why it is the all-rounder and usually the better value per scoop. Marine collagen is type I only, so it leans towards skin, and its peptides are smaller, which some people prefer for absorption. The catch is where it comes from. Marine collagen is made from fish, so it is out for anyone with a fish allergy, and those powders often carry other trace allergens too. If you want one tub to look after the whole body, reach for bovine. If your focus is skin and fish sits fine with you, marine is a fair pick.

Hydrolysed is the word doing the real work on a collagen label. It means the long collagen chains have been broken down into short peptides small enough for your body to absorb, rather than the intact protein you would get from a bone broth. That size is measured in kilodaltons, and smaller is the whole point: good hydrolysed peptides sit at a low molecular weight, under about 1 kilodalton, which is what lets them cross the gut wall and get to work. A quality collagen states a low kilodalton score, as Chief's does, and one that stays quiet about the number is often hiding a bigger, clumsier peptide. Think of it as the difference between a whole log and kindling. Same wood, very different to actually use.

A clean collagen is mostly, ideally entirely, collagen. Turn an unflavoured tub around and the ingredient list should read as one line: hydrolysed collagen, with no sweeteners, sugar alcohols or fillers padding it out. Flavoured powders are where it gets murkier, so check what is doing the sweetening. Monk fruit is clean and passes; sugar alcohols like erythritol and xylitol are the ones that leave some people bloated. Sourcing is the other tell. Grass-fed is a genuine quality signal for bovine collagen because it reflects how the animal was raised and fed. Chief's unflavoured collagen is 100% hydrolysed grass-fed bovine collagen and nothing else, which is the whole idea.

Here is the part most labels would rather you skipped. Collagen is made from animal hide or fish, and contaminants like heavy metals, pesticides and glyphosate concentrate as they move up the food chain, so they can end up in the finished powder you stir into your morning coffee. This is not scaremongering. In 2025 an independent testing project analysed 160 protein powders and found nearly half exceeded at least one safety threshold for heavy metals. That does not make every tub unsafe, but it does make testing the difference between hoping and knowing. Look for a brand that has its collagen third-party tested for heavy metals, pesticides and glyphosate, and that will actually show you the results. Chief tests its collagen for all three.

Collagen is worth trying for a lot of people, but it is not for everyone and it is honest about its limits. It is not a complete protein, so it should not be your only protein source, especially if you train and need real muscle repair. Marine collagen is made from fish, which rules it out for anyone with a fish allergy, and marine powders can also carry traces of milk, soy, nuts, sesame or egg. All collagen is animal-sourced, from cattle or fish, so none of it suits vegans or vegetarians. And if you are pregnant, breastfeeding or managing a health condition, check with your healthcare provider before you add anything new.