What FDA's new spirulina extract rule means for supplement coatings
By Jake, founder · Published · Source dated
FDA amended the color additive listing for spirulina extract, effective March 23, 2026. The amended regulation expands use to human foods generally and specifies heavy metal limits. The source text lists prior approved uses, but does not explicitly state whether the coating use for supplement tablets and capsules is retained in the final description.
What exactly changed in the spirulina extract rule?
The FDA amended 21 CFR 73.530 for spirulina extract. The final rule states the color additive may be safely used for coloring human foods generally at levels consistent with good manufacturing practice, with specific exceptions for products regulated by the USDA, infant formula, and certain standardized foods.
The source text does not provide the previous regulatory text or state directly how the new uses differ from the old ones. It does mention that the petition proposed to expand the use of spirulina extract.
The amended regulation includes specifications for lead, arsenic, mercury, and cadmium. The source text says these heavy metal specifications were lowered and a cadmium specification was added, but it does not provide the previous limits or any numerical comparison.
The final rule is effective March 23, 2026. Objections and requests for a hearing must be submitted by March 9, 2026.
Does the new rule still allow spirulina extract in supplement coatings?
The source text describes the previous approval for spirulina extract as covering specific food categories, including coating formulations applied to dietary supplement tablets and capsules. However, the amended regulatory text quoted in the source uses the broad phrase 'human foods generally' and does not explicitly mention supplement coatings.
Because the source does not state that the coating use is retained, excluded, or specifically affected, we cannot confirm from this text whether the previous allowance for that use continues. The final rule's scope is stated as human foods generally, subject to the listed exceptions.
If you are relying on spirulina extract as a color in your supplement coating, the safest reading from the source is that the final regulation text does not single out supplement coatings. You may want to check the full updated regulation or consult with a regulatory expert to determine whether your use falls under the new broad authorization.
What are the new heavy metal specifications?
The amendatory instruction in the source text revises the specifications in 21 CFR 73.530(b) to include the following limits: lead not more than 0.2 mg/kg, arsenic not more than 0.3 mg/kg, mercury not more than 0.1 mg/kg, and cadmium not more than 0.3 mg/kg.
The source text says the petition proposed to lower the heavy metal specifications for lead, arsenic, and mercury, and to add a specification for cadmium. However, it does not state what the previous limits were.
The specifications also state that spirulina extract must be free from impurities other than those named, to the extent such impurities may be avoided by good manufacturing practice, and must be negative for microcystin toxin.
Does this affect my supplement brand if I don't use spirulina extract?
The rule is limited to spirulina extract as a color additive. If your products do not use spirulina extract, this specific amendment does not directly change any color additive requirements for your products.
The source text does not address other color additives or general supplement compliance. No broader regulatory changes are described in this document.
This rule is about an ingredient specification and allowed use, not about Amazon requirements, GMP documentation, or testing rules for supplements generally.
What should I do next if my supplement uses spirulina extract in the coating?
Consider confirming with your contract manufacturer or ingredient supplier that the spirulina extract you use meets the amended heavy metal limits stated in the source: lead 0.2 ppm, arsenic 0.3 ppm, mercury 0.1 ppm, cadmium 0.3 ppm, and negative for microcystin.
Ask for documentation that the lot of spirulina extract used in your product meets those specifications. A Certificate of Analysis for the color additive may show these metals.
If your product uses a coating that contains spirulina extract, a document reviewer might look for evidence that the color additive complies with the current specification, but the source text does not discuss document review.
Keep records of your supplier's specification sheets and any test results, because the source does not describe any new recordkeeping requirement for this rule.
What the source does not say
The source text does not state the previous heavy metal limits, so we cannot say how much they were lowered.
The source text does not explicitly confirm that the prior allowance for coating formulations applied to dietary supplement tablets and capsules is retained. It lists the prior approved uses in the background section and then describes the amended regulation in broad terms.
The source text does not discuss Amazon, TIC verification, or any documentation requirements for selling dietary supplements online.
The source text does not impose any new labeling requirements or mention a grace period for existing inventory.
Frequently asked questions
- When does the new spirulina extract rule take effect?
- The order is effective March 23, 2026, according to the DATES section of the source text. Objections and requests for a hearing were due by March 9, 2026.
- What are the heavy metal limits for spirulina extract now?
- The amendatory instruction lists lead not more than 0.2 mg/kg, arsenic not more than 0.3 mg/kg, mercury not more than 0.1 mg/kg, and cadmium not more than 0.3 mg/kg. It also requires negative for microcystin toxin.
- Does the rule say spirulina extract can still be used in supplement coatings?
- The source text does not explicitly say. It describes prior approval for coating formulations applied to dietary supplement tablets and capsules, but the amended regulation text uses 'human foods generally' without listing that specific use. We cannot confirm from this source whether that use remains allowed.
- Is spirulina extract now approved for all foods?
- The amended regulation states spirulina extract may be safely used for coloring human foods generally, except for products subject to USDA regulation, infant formula, and certain standardized foods unless the standard authorizes the color.
- What should I ask my supplement manufacturer if we use spirulina extract?
- Consider asking for documentation that the spirulina extract meets the amended heavy metal specifications: lead 0.2 ppm, arsenic 0.3 ppm, mercury 0.1 ppm, cadmium 0.3 ppm, and negative for microcystin. Keep that documentation with your product records.
Related guides
Sources
- Federal Register — Listing of Color Additives Exempt From Certification; Spirulina Extract accessed 2026-08-17
Written from the source text above and checked against it before publishing: every date, figure and section cited appears in the source. Information, not legal advice.