5 Best Chelated Copper Supplements - July 2022 - BestReviews Popular amino acid chelated copper supplement. Inexpensive. Chelated in rice protein, so it's soy-free. Helps reverse gray hairs. Solid and trusted choice for copper deficiency issues. Minor complaints of capsules arriving rancid. Large capsules hard for some to swallow. Pure Encapsulations Copper (Glycinate) (Chelated) Check Price Trusted Brand