Prop 65 and supplements: lead, safe harbor warnings, online sales and the 2028 short-form deadline

Prop 65 matters for supplements because ingredients can carry traces of listed chemicals such as lead, which plants can take up from the environment. Unless the business can show exposure is at or below the safe harbor level, it must give a clear and reasonable warning. Online, the warning goes on the product display page, behind a WARNING link on that page, or in front of the buyer before checkout.

What is Proposition 65?

Proposition 65 is a California initiative that voters approved in 1986, officially the Safe Drinking Water and Toxic Enforcement Act of 1986 (OEHHA). It requires businesses to give clear and reasonable warnings before knowingly and intentionally exposing anyone to a chemical on the state's list, which has grown to more than 800 chemicals since it was first published in 1987. Once a chemical is listed, businesses have 12 months to comply.

California's Office of Environmental Health Hazard Assessment (OEHHA) runs the program and writes the warning rules. The Attorney General enforces the law, and so can district attorneys, city attorneys in cities of more than 750,000 people and any individual acting in the public interest.

Businesses with fewer than 10 employees are exempt from the warning requirements; the Attorney General's FAQ puts it as 9 or fewer (AG FAQ). OEHHA adds a caution: a small business may still have contractual obligations or indemnification agreements related to Prop 65 warnings (OEHHA FAQ). If you sell through retailers or marketplaces, read what your agreements require before you rely on the exemption.

OEHHA's own short explainer shows what the warnings mean from the shopper's side:

Why do supplements need Prop 65 warnings?

Because of what can come along with the ingredients. FDA notes that lead may be present in food from the environment where foods are grown, raised or processed, that lead in the environment can be taken up by plants and enter the food supply, and that the agency monitors and regulates levels of lead in foods (FDA).

Lead is on the Prop 65 list for cancer and for developmental, male and female reproductive toxicity; it was listed for developmental and male reproductive toxicity on February 27, 1987 (OEHHA on lead).

A business has "safe harbor" from the warning requirement when the exposure is at or below the chemical's safe harbor level. For cancer, that is the No Significant Risk Level: the exposure that would cause no more than one excess case of cancer in 100,000 people over a 70-year lifetime. For reproductive harm, it is the Maximum Allowable Dose Level, which builds in a margin by dividing the no-observable-effect level by 1,000. For lead, OEHHA lists:

• 0.5 micrograms a day: the Maximum Allowable Dose Level for reproductive toxicity.
• 15 micrograms a day: the No Significant Risk Level for cancer, by mouth.

The reproductive level is 30 times lower, so for lead it is the number that decides whether any warning is needed.

Both levels are per day, so the question is never only "how much lead is in the powder" but "how much lead does a day of use deliver". The arithmetic, with made-up numbers:

Lead from a day of use

Illustrative numbers, not a typical level

Lead per day (µg)=lead result (µg per g) × grams per serving × servings per day

A made-up result of 0.2 µg/g × a 2 g scoop × 1 serving = 0.4 µg a day, under the 0.5 µg level. Two scoops a day = 0.8 µg, over it.

Three things follow from that formula. Your directions for use are part of the math: a bigger scoop, or a second serving a day, raises the exposure. Lab sensitivity matters near the line: a result reported as "< LOQ" needs a quantitation limit low enough to tell 0.4 from 0.8 micrograms a day. And because the business carries the burden of proving a warning isn't required, the lot results and the calculation are what you would show if challenged.

Where does a Prop 65 warning go online?

To count as a safe harbor warning for an internet purchase, a warning must meet the content rules and be provided in one or more of three ways (27 CCR 25602):

1. a warning on the product display page;
2. a clearly marked hyperlink using the word "WARNING" (or "CA WARNING" or "CALIFORNIA WARNING") on the product display page, linking to the warning;
3. an otherwise prominently displayed warning provided to the buyer before the purchase is completed.

A warning is not prominently displayed if the buyer has to search for it in the general content of the website. The website warning also comes on top of the one on or with the product: OEHHA's FAQ says an online seller who wants safe harbor protection provides a warning on or with the product and online. Its example is a warning label on the product plus a photo of that label on the website, so the buyer sees the warning before completing the purchase and again before exposure.

Here is how that sorts out on a product page:

Online Prop 65 warnings: what counts

Meets the online ruleCounts

• The full warning on the product display page
• A clearly marked "WARNING" link on that page that opens the warning
• The warning shown prominently before the purchase is completed
• A readable photo of the product's warning label, shown before purchase (OEHHA's example)

Not enoughDoesn't count

• A warning the buyer has to search the site to find
• A link labeled "Legal" or "Info" instead of "WARNING"
• A website warning with no warning on or with the product
• A warning on the bottle only, with nothing before purchase

A VSL funnel has two places where the buyer meets the product and the price: the offer section of the VSL page, where the bundles appear, and the checkout on your store or cart. A cautious reading puts the warning, or a WARNING link, in both: beside the bundles, and on the checkout page before the order button. A legal footer at the bottom of a long sales page is close to the general content a buyer would have to search through, so treat it as a backup, not the warning.

In RevvyScales, the offers and the buy button stay hidden until the pitch second you set (player conversion features). A short content section carrying the warning (content blocks), placed beside the bundle offers, is on the page whenever the offers are. Checkout stays on your own store or cart platform, so set the warning up there too.

What does a Prop 65 warning for supplements say?

The safe harbor warning has three parts, set out in 27 CCR 25603:

1. The symbol: a black exclamation point in a yellow equilateral triangle with a bold black outline. If the label isn't printed in yellow, the symbol may be black and white.
2. The signal word: "WARNING:", "CA WARNING:" or "CALIFORNIA WARNING:", in capital letters and bold.
3. The text. The long form for reproductive harm, with lead as the named chemical, reads: "This product can expose you to chemicals including lead, which is known to the State of California to cause birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov." When one chemical is warned about for both endpoints, the sentence ends "to cause cancer and birth defects or other reproductive harm", followed by the same website line.

Which endpoints to name is a decision for your exposure assessment and your lawyer.

The short form is the compact version for labels, and it has changed. Under amendments filed on November 26, 2024 and operative on January 1, 2025, the new short-form text names a chemical:

Both versions carry the triangle symbol. The cancer version of the new text starts "Cancer risk from exposure to", and a combined version covers both endpoints. On the website, if the label uses a short form, the online warning may use the same content, and for internet purchases made before January 1, 2028, a retailer has 60 calendar days after notice of an updated short-form warning to post it online.

The dates in one place:

Prop 65 dates for supplement sellers

1. 1986Voters approve Proposition 65The Safe Drinking Water and Toxic Enforcement Act of 1986.
2. Feb 27, 1987Lead listedFor developmental and male reproductive toxicity, in the year the first list was published.
3. Nov 26, 2024Short-form amendments filedNew short-form warnings name a chemical.
4. Jan 1, 2025Amendments operativeThe new short-form wording can be used.
5. Jan 1, 2028New short form required for safe harborProducts manufactured and labeled earlier may keep the old wording, whenever they are sold.

Test or warn: which route fits your brand?

Brands land on one of two routes.

Test and document. Test each lot for lead and the other listed metals your specification covers, calculate the exposure from a day of use, keep the results, and warn whenever you can't show the exposure is at or below the safe harbor level. This route matches OEHHA's own guidance, which says a business is discouraged from providing a warning that is not necessary and suggests consulting a qualified professional when you believe a warning isn't needed.

Warn on everything. Some sellers put a warning on every product sold into California instead of testing. It saves lab costs, but it runs against OEHHA's advice on unnecessary warnings, it puts a sentence about cancer or birth defects next to your offer, and it still has to be worded and placed correctly to count.

Either way, the test results are the foundation, and reading them well is a skill of its own:

Who is responsible for the Prop 65 warning?

OEHHA's regulations put primary responsibility on product manufacturers, producers and the other businesses upstream of the retailer. They can comply by putting the warning on the label, or by sending a written notice to the retailer's authorized agent and receiving an acknowledgment, renewed at least once a year. Retailers are responsible for placing and maintaining the warning materials they receive (OEHHA FAQ).

A direct-to-consumer brand that sells on its own site usually holds both jobs: it controls the label, and it runs the pages where the sale happens. If you also sell through retailers or a marketplace, agree in writing who provides which warning; those agreements are also where the small-business exemption meets contractual obligations.

What is a Prop 65 60-day notice?

A private party can sue in the public interest only after giving at least 60 days' notice of the alleged violation to the business, the Attorney General and the appropriate district attorney and city attorney, and only if those officials haven't taken action (AG FAQ). Civil penalties can reach $2,500 per day for each violation. Settlements must be provided to the Attorney General and are posted on its website, and a court has to find any penalty amount in a private settlement reasonable.

The notices are searchable. The Attorney General's 60-day notice search holds records from 1988 to the present and filters by chemical, source or product, defendant and plaintiff. Before launch, search your main ingredients and your product type: notices on similar products show which chemicals enforcers are looking for.

If a notice arrives:

1. Don't ignore it. The 60 days are the window before a lawsuit can be filed.
2. Pull the COAs and exposure calculations for the lots and products named.
3. Take screenshots of where your warnings appear today: label, product page, VSL page, checkout.
4. Call a Prop 65 lawyer before you reply.

A Prop 65 checklist for supplement brands

Work through this before your first California sale, and again whenever a formula, a supplier or a label changes:

Prop 65 for a supplement brand

• Count employees: fewer than 10 is exempt, but check retailer and marketplace contracts
• Test each lot for lead and the other listed metals in your specification
• Convert each result to micrograms per day at the label's daily serving
• Compare with the safe harbor levels (lead: 0.5 µg a day for reproductive harm)
• Keep the results and calculations on file for every lot
• If you warn: the symbol, the signal word and the chemical named
• Warning on or with the product, and online before purchase
• Beside the offers on the VSL page, and on the checkout page
• Short-form labels switched to the new wording before January 1, 2028
• Search the Attorney General's 60-day notices for your ingredients

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For the rest of the label, see supplement label requirements; for where Prop 65 fits in a launch, see how to start a supplement company; and for claims and disclosures inside the video, see the VSL compliance guide.