If you are looking for a collagen "without lead," the honest answer is that the goal is not a magic lead-free label, it is transparency and third-party testing. Trace heavy metals exist throughout the food supply, so what separates a trustworthy collagen is whether the company actually tests for them, shares that it does, and holds itself to a real standard. Yonder collagen is third-party tested for purity and heavy metals, and we hold ourselves to and beyond California's strict Prop 65 standard. Here is what that means and how to evaluate any collagen for yourself.
Where do heavy metals in collagen come from?
Heavy metals like lead, cadmium, arsenic, and mercury occur naturally in soil and water, and they can accumulate in plants and animals through the environment. Because collagen is an animal-derived protein concentrated from hides and connective tissue, trace metals present in the environment can carry through into the finished powder.
This is not unique to collagen, it is true of many whole foods and supplements, from leafy greens to protein powders to chocolate. The point is not panic. The point is that a responsible brand measures what is actually in the product instead of assuming.
Is a little lead in a supplement a problem?
Regulators treat lead carefully because there is no recognized benefit to consuming it, which is why California's Proposition 65 sets some of the strictest exposure thresholds in the country. For a product you take every day, small amounts matter more than they would in something you consume once in a while, simply because the exposure is repeated.
That is exactly why daily supplements deserve daily-habit-level scrutiny, and why testing, not marketing language, is what should earn your trust.
What is Prop 65, and why does it matter for collagen?
California's Proposition 65 requires warnings for products that expose consumers above set thresholds for certain substances, including lead. It is one of the toughest standards in the United States, and many supplements sold nationwide are formulated to meet it.
When you are comparing collagens, a brand that talks openly about meeting or exceeding Prop 65 is signaling that it actually measures heavy metals. A brand that says nothing usually has not looked.
Why isn't most collagen tested for heavy metals?
For the same reasons most collagen is not tested for glyphosate: it is not legally required, and rigorous testing costs money and has to be repeated. So a large share of the market has never published heavy-metal data at all.
That silence is the problem. Without third-party testing, "pure" and "clean" on the front of a bag are just words.
How is heavy-metal testing actually done?
Credible testing uses an independent, accredited laboratory (ISO 17025 accredited labs are the standard) to measure each metal against established limits. The most trustworthy brands test by batch or lot rather than once at launch, because raw materials change over time. Third-party means the lab has no stake in the result.
This is the difference between "we think it is clean" and "an outside lab measured it."
Is bone broth or protein powder any safer?
Not automatically. Bone broth is nutritious, but its mineral and contaminant content varies batch to batch and it is rarely tested for heavy metals. General protein powders have repeatedly been flagged by independent testers for heavy-metal content. The common thread is the same: without testing, you cannot know.
Isolated collagen peptides from a company that publishes its testing give you a more consistent, measurable, and verifiable option than an untested broth or blend.
What to look for in a clean, tested collagen
| What to look for | Why it matters | Yonder |
|---|---|---|
| Third-party heavy-metal testing | An outside lab measures lead, cadmium, arsenic, mercury | Yes |
| Meets or exceeds Prop 65 | A real, strict regulatory benchmark | Yes |
| Certified Glyphosate Residue-Free by The Detox Project | Independent purity certification | Yes |
| Grass-fed and grass-finished, pasture-raised | Cleaner inputs from the start | Yes |
| Single ingredient, no fillers | Fewer places for contaminants to hide | Yes |
If a collagen can show you all of this, you are looking at a brand that takes purity seriously. Most cannot.
Why we test the way we do
We started Yonder because we wanted a collagen clean enough for our own families, and we were not satisfied with assurances we could not verify. So we built purity and testing into the product from the start.
Yonder collagen is third-party tested for purity and heavy metals, certified Glyphosate Residue-Free by The Detox Project, sourced from 100% grass-fed and grass-finished, pasture-raised cattle, and made from a single ingredient. We hold ourselves to and beyond Prop 65. One to two scoops gives you 10 to 20g of collagen plus 9 to 18g of clean, grass-fed protein, flavorless and easy to stir into any drink.
We would rather earn your trust with testing than with adjectives.
Shop Yonder Grass-Fed Collagen Peptides (Flavorless)
What the research says about collagen peptides
What clean, tested collagen peptides are well-studied to support. (Studies referenced are indexed on PubMed.)
- Skin: Daily collagen peptides significantly improved skin elasticity in a double-blind RCT (Proksch et al., 2014) and reduced eye-wrinkle volume in another (Proksch et al., 2014). Supports skin elasticity and hydration.*
- Bone: A 12-month RCT in postmenopausal women showed increased bone mineral density (Koenig et al., 2018). Supports bone health in midlife.*
- Joints: RCTs show improved joint comfort and function (Genc et al., 2025). Supports joint comfort during daily activity.*
- Nails: Collagen peptides increased nail growth and reduced brittleness (Hexsel et al., 2017). Supports nail strength.*
- Muscle composition: With resistance activity, collagen peptides increased fat-free mass (Zdzieblik et al., 2021). Supports muscle composition when paired with activity.*
Frequently asked questions
Can collagen ever be completely free of heavy metals?
Trace heavy metals exist throughout the food supply, so the meaningful question is not "zero," it is whether a brand tests, publishes, and meets a strict standard like Prop 65. Yonder does.
What heavy metals should collagen be tested for?
Primarily lead, cadmium, arsenic, and mercury, measured by an independent accredited lab.
Is grass-fed collagen automatically low in heavy metals?
Cleaner sourcing helps, but it is not a substitute for actual testing. Look for both.
How much should I take daily?
About 10 to 20g, which is one to two scoops of Yonder.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
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