Cal. Health & Safety Code § 110423.2

(a) It is a misdemeanor for any manufacturer, wholesaler, retailer, or other person, to sell, transfer, or otherwise furnish any of the following to a person under 18 years of age:
1. (1) A dietary supplement containing an ephedrine group alkaloid.
2. (2) A dietary supplement containing any of the following:
  1. (A) Androstanediol.
  2. (B) Androstanedione.
  3. (C) Androstenedione.
  4. (D) Norandrostenediol.
  5. (E) Norandrostenedione.
  6. (F) Dehydroepiandrosterone.
(b) A seller shall request valid identification from any individual who attempts to purchase a dietary supplement set forth in subdivision (a) if that individual reasonably appears to the seller to be under 18 years of age.
(c) Notwithstanding subdivisions (a) and (b), a retail clerk who fails to request identification pursuant to subdivision (b) shall not be guilty of a misdemeanor pursuant to subdivision (a), subject to any civil penalties, or subject to any disciplinary action or discharge by his or her employer. This subdivision shall not apply to a retail clerk who is a willful participant in an ongoing criminal conspiracy to violate this article.