Keeping any supplement safely stored away from children is worth a direct, practical answer, whatever the specific formula.
Store the bottle in its original container, out of reach and out of sight of children, in the same way you'd store any medication or supplement in your home — a genuine consideration given both the liquid-dropper format and the pharmacologically active berberine content.
Contact your local poison control center or seek immediate medical attention if a child accidentally ingests some, and bring the physical bottle with you so medical staff have accurate ingredient information on hand.