California Proposition 65

Last updated: September 15, 2026

Every bottle of Your Birth Control's Best Friend now carries this on the label:

WARNING: Cancer and Reproductive Harm — www.P65Warnings.ca.gov

It was not on our earlier bottles. To be clear about what that does and does not mean: the formula has not changed. Same capsule, same ingredients, same amounts. What changed is our manufacturer's labeling policy, and this page explains why.

What is Proposition 65?

Proposition 65 is a California law, formally the Safe Drinking Water and Toxic Enforcement Act of 1986. It was passed by California voters, not by a health agency, and it does one main thing: it requires businesses to warn Californians before exposing them to any chemical on a state-maintained list of substances known to cause cancer, birth defects or other reproductive harm.

The list now runs to roughly 900 chemicals. It includes what you would expect — industrial solvents, pesticides, tobacco smoke — and also a number of elements that occur naturally in soil and water, including lead and cadmium. Those last two are the reason Proposition 65 warnings turn up on food, coffee, chocolate, protein powder, seaweed, prenatal vitamins and mineral supplements.

The law is a disclosure law. It sets no limit on what may be sold, requires no product to be reformulated, and makes no finding about any individual product. It requires a warning.

Why does this warning appear on our capsules?

We will be straightforward with you: this warning is on our bottles because our manufacturer now applies it to every product it makes, for every brand it works with, regardless of what testing shows.

That sounds evasive until you understand how the law is enforced. Proposition 65 is enforced largely by private parties rather than by the state. Any individual or group may serve a notice of violation on a company selling into California, and a plaintiff who prevails collects a share of the penalties, which can run up to $2,500 per day per violation. Defending one of these notices costs more than settling it, and settling costs more than warning. So across the supplement industry, contract manufacturers have arrived at the same conclusion: warn on everything, and take the question off the table.

California has also continued to revise the rules — the required warning language itself changed as recently as 2025 — which gives manufacturers one more reason to apply the broadest warning available rather than make a product-by-product judgment.

The result is a warning that tells you very little about the specific bottle in your hand. That is a real limitation of the law, and it is worth knowing about before you draw conclusions from it.

Which chemicals are we talking about, and where do they come from?

For a mineral-containing supplement, the chemicals at issue are almost always heavy metals present in trace amounts — most often lead, and sometimes cadmium.

Neither one is added to anything. Both are naturally present in the earth's crust. Plants take them up from soil and water, and minerals mined from the ground carry them in trace quantities. Our capsules contain magnesium, zinc and selenium, all of which are mineral ingredients that come out of the ground, and vitamin and botanical-derived ingredients grown in soil. There is no version of these ingredients that contains zero lead, because there is no soil that contains zero lead. The same is true of spinach, sweet potatoes, cacao and bone broth.

This is why California's own guidance on food notes that a warning "does not mean that these foods and beverages should never be consumed."

How low are California's thresholds?

This is the part that explains almost everything about why these warnings are so widespread.

California sets two kinds of threshold, and both are built to be deliberately conservative:

• For cancer, the state sets a "No Significant Risk Level" — the exposure level calculated to result in no more than one additional case of cancer per 100,000 people exposed daily over a 70-year lifetime.
• For reproductive harm, the state starts from the highest dose shown to produce no observable effect at all in studies, then divides that number by 1,000.

For lead, the reproductive-harm threshold that results is 0.5 micrograms per day. A microgram is one millionth of a gram. For context, that figure is a small fraction of what a typical adult takes in daily from ordinary food and drinking water, and it sits well below the intake limits used by federal regulators and by the U.S. Pharmacopeia for supplements. For cadmium, the equivalent threshold is 4.1 micrograms per day.

A threshold set that low is not a line between safe and dangerous. It is a line drawn far below any observed effect, on purpose, for a law whose only consequence is a label.

Does the warning mean the product is unsafe?

No — and we want to be precise about what we are and are not saying.

A Proposition 65 warning is a statement about potential exposure to a listed chemical. It is not a determination by California, or by anyone else, that a product is harmful, contaminated, out of specification, or unsuitable for use. Products carrying these warnings are sold legally throughout California, including in health food stores, pharmacies and prenatal aisles.

What the warning cannot tell you is anything about how a specific product was made or tested. That is a fair question to ask us, and the answer is below.

Does this apply outside California?

The legal requirement applies only to products sold in California. But labels are printed in a single run for the whole country, so the warning appears on every bottle we ship, wherever you live. You have not received a different or lesser product because the warning is on your label.

Still have questions?

Ask us. Email hello@takemodiv.com and a person will answer you. If you want to read California's own materials rather than ours, the state maintains an explanation for consumers at P65Warnings.ca.gov, with a section specific to food and supplements at P65Warnings.ca.gov/products/food.

If you are pregnant, nursing, or managing a health condition, talk to your clinician before starting any supplement — that advice has nothing to do with Proposition 65 and everything to do with it being the right thing to do.