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Last modified: May 23, 2024

Proposition 65 label requirements (California only)

Overview: What is Proposition 65?

Proposition 65 (Prop 65) requires businesses to warn Californians about possible exposures to chemicals that can cause cancer, birth defects, or other reproductive harm. The state of California requires dietary supplement companies to include a Prop 65 warning label on products containing certain levels of one or more chemicals linked to cancer, birth defects, or other reproductive harm.

Good quality supplement manufacturers take every precaution possible to ensure a safe product. We are confident that the brands we carry care deeply about delivering products that are not only safe but beneficial to patient health. If you see the Prop 65 warning on a product, it demonstrates that that company complies with the law which is a very good sign.


Read more about Proposition 65 on the Fullscript blog

How do I know what ingredient(s) are affected?

According to the American Cancer Society, as of August 2018, the label should name at least one chemical of concern, but it doesn’t require all affected ingredients to be listed. If you have questions about the product you received, we recommend reaching out to the brand directly. Fullscript only has information about the ingredients affected by Prop 65 as described on the product’s label.  

Are products labeled with a Proposition 65 warning safe?

A Prop 65 warning doesn’t mean that using an individual product will cause cancer or reproductive harm when used as directed. There continues to be much debate over what the toxic level or cumulative toxic level of each different substance is. 

Prop 65 guidelines are much more rigorous than many of the Environmental Protection Agency’s (EPA) and the U.S. Food and Drug Administration’s (FDA) guidelines for chemical exposure. For example, the Prop 65 threshold for any product containing lead is 0.5 mcg, whereas the FDA’s limit for daily lead exposure, also known as the Interim Reference Level (IRL), is 12.5 mcg per day. Many foods contain naturally-occurring lead from the soil they are grown in; for example, one ounce of dark chocolate can contain about 0.92 mcg of lead, which would exceed the safe lead limit by Prop 65 standards.

Reference: Lead Contamination in Cocoa and Cocoa Products: Isotopic Evidence of Global Contamination

Identifying California-only products

Identifying California-only products in the catalog

Some brands, such as Ortho Molecular Products and Carlson Labs, require the California-only labeled version of their products to be purchased when shipping to California (if available). These products are labeled with the Prop 65 warning legally required when ingredients affected by Prop 65 ship to this state. ‘California Only’ products are identical to the original product; the only difference is the presence of a Prop 65 warning on the packaging.

Other brands affected by Prop 65 will simply add a warning sticker to the product before shipping and don’t have California-only products. 

The California-only product in the catalog.

Viewing a California Only product in the catalog. Products with this label can only be shipped to the state of California. 


Some brands aren’t able to ship products affected by Prop 65 to California and don’t have alternative products to purchase. If you’re a patient, we recommend reaching out to your practitioner for a new recommendation if these items are removed from your order.


Identifying California-only products during checkout

When a practitioner or patient enters a California address during checkout, a California Warning dropdown will appear beneath any product subject to proposition 65 regulations. The warning information in the dropdown is dynamic and will show one out of 36 applicable chemicals, as well as speak to one or multiple associated risks.

A proposition 65 warning in checkout

A proposition 65 warning in checkout.

Order update notifications

If either of the following scenarios occurs, one of our Customer Success agents will contact you to communicate a change has been made to your order due to label requirements resulting from prop 65:

  1. You’ve purchased a product without a California-only label (i.e., unlabeled) where a California-only label is required. The order is shipping to California. 
    What to expect: We’ll remove the product from your order and issue a refund. We’ll direct you to purchase the California-only version of the product, if available.
  2. You’ve purchased a product with a California-only label, and your order is shipping to a state other than California.
    What to expect: We’ll remove the product from your order and issue a refund. We’ll direct you to purchase the product without the Prop 65 label. 


‘California Only’ products are identical to the original product; the only difference is the presence of a Prop 65 warning on the packaging

References & resources

For references and further information, please visit:

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