ATLANTA (AP) — Georgia’s governor on Thursday signed a bill putting new regulations on the production and sale of products containing kratom, a plant-based supplement.

The law, which takes effect Jan. 1, prohibits the sale of kratom to anyone under 21 and says it must be kept behind a counter or in a display area that is only accessible to store employees. It also limits the concentration of kratom’s main chemical components in products sold in Georgia, imposes new labeling requirements and adds penalties for violations.

Extracted from the leaves of a tropical tree native to Southeast Asia, kratom is used to make capsules, powders and liquids. It’s often sold in gas stations or smoke shops, marketed as an aid for pain, anxiety and drug dependence.

Proponents of kratom say it’s a safe, natural herbal supplement that can help manage pain and ease the effects of opioid withdrawal. An estimated 1.7 million Americans used kratom in 2021, according to a national survey by the Substance Abuse and Mental Health Services Administration.