Common Names

  • Seasilver

For Patients & Caregivers

How It Works

Seasilver does not prevent or cure cancer.

Promoters of seasilver claim that the product is effective against cancer and other diseases. There is no scientific evidence, in the form of laboratory studies, animal studies, or clinical trials, to support such claims.

In June, 2003 the Federal Trade Commission (FTC) accused Seasilver’s marketers of promoting Seasilver with false and fraudulent claims at which point the Food and Drug Administration (FDA) seized nearly $5.3 million worth of the product. Seasilver USA has since agreed to comply with strict FDA and FTC guidelines regarding the marketing of its product.

Purported Uses
  • To detoxify the body Evidence is lacking to support this claim.
  • To prevent and treat cancer Evidence is lacking to support this claim.
Patient Warnings
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For Healthcare Professionals

Brand Name
Seasilver™ (Seasilver USA, California, USA)
Clinical Summary

SeasilverTM is a dietary supplement that contains aloe vera, a combination of seaweed, pau d’arco, and cranberry concentrate. It has been promoted as a natural immune enhancer. While the exact properties of this product are unclear, certain ingredients may not be appropriate for cancer patients. Aloe vera contains anthraquinone which may irritate the GI system, leading to stomach upset and diarrhea. Certain seaweed products contain carrageenan and algin. At high doses these substances can impair absorption of oral medications. Seaweed products can also contain contaminants, which pose a risk for immunocompromised patients. Pau d’arco is derived from bark that has potential anticoagulant effects due to coumarin content. It is typically prepared in 20% ethyl alcohol, but the final alcohol concentration of this product is not listed (1). Cranberry is acidic, and while the pH of this product is unknown, high concentrations may cause stomach irritation (3). No studies have shown the efficacy of this product, which is distributed through a multi-tiered marketing scheme.

In June 2003, the FDA seized nearly $5.3 millions worth of product from Seasilver USA’s San Diego headquarters (3). Since then Seasilver has agreed to comply with strict FDA and FTC guidelines regarding marketing of its product (4).

Purported Uses
  • Cancer prevention
  • Detoxification
  1. Brinker F. Herb Contraindications and Drug Interactions, 2nd ed. Sandy (OR): Eclectic Med Publications; 1998.
  2. Bisset NG. Herbal Drugs and Phytopharmaceuticals. Boca Raton: CRC Press; 1994.
  3. Federal Trade Commission. No Silver Lining for Marketers of Bogus Supplement; Federal Agencies Crack Down on Health Fraud. June 19, 2003. Accessed August 15, 2019. .
  4. Consumer Health Digest. Seasilver Penalties Announced. March 30, 2004. Accessed August 15, 2019.
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