BPC §17508: (a) It shall be unlawful for any person doing business in California and advertising to consumers in California to make any false or misleading advertising claim, including claims that (1) purport to

(a) It shall be unlawful for any person doing business in California and advertising to consumers in California to make any false or misleading advertising claim, including claims that (1) purport to be based on factual, objective, or clinical evidence, (2) compare the product’s effectiveness or safety to that of other brands or products, or (3) purport to be based on any fact. (b) Upon written request of the Director of Consumer Affairs, the Attorney General, or any city attorney, county counsel, or district attorney, any person doing business in California and in whose behalf advertising claims are made to consumers in California, including claims that (1) purport to be based on factual, objective, or clinical evidence, (2) compare the product’s effectiveness or safety to that of other brands or products, or (3) purport to be based on any fact, shall provide to the department or official making the request evidence of the facts on which the advertising claims are based. The request shall be made within one year of the last day on which the advertising claims were made. Any city attorney, county counsel, or district attorney who makes a request pursuant to this subdivision shall give prior notice of the request to the Attorney General. (c) The Director of Consumer Affairs, Attorney General, or any city attorney, county counsel, or district attorney may, upon failure of an advertiser to respond by adequately substantiating the claim within a reasonable time, or if the Director of Consumer Affairs, Attorney General, city attorney, county counsel, or district attorney shall have reason to believe that the advertising claim is false or misleading, do either or both of the following: (1) Seek an immediate termination or modification of the claim by the person in accordance with Section 17535. (2) Disseminate information, taking due care to protect legitimate trade secrets, concerning the veracity of the claims or why the claims are misleading to the consumers of this state. (d) The relief provided for in subdivision (c) is in addition to any other relief that may be sought for a violation of this chapter. Section 17534 shall not apply to violations of this section. (e) Nothing in this section shall be construed to hold any newspaper publisher or radio or television broadcaster liable for publishing or broadcasting any advertising claims referred to in subdivision (a), unless the publisher or broadcaster is the person making the claims. (f) The plaintiff shall have the burden of proof in establishing any violation of this section. (g) If an advertisement is in violation of subdivision (a) and Section 17500, the court shall not impose a separate civil penalty pursuant to Section 17536 for the violation of subdivision (a) and the violation of Section 17500 but shall impose a civil penalty for the violation of either subdivision (a) or Section 17500.