Purity >98%. L-Homopropargyl glycine is a reactive methionine analog that contains an alkyne moiety. It is readily inserted into newly-synthesized proteins in place of methionine. L-Homopropargyl glycine can then be labeled or captured through click chemistry. This approach represents a fast, sensitive, and non-radioactive alternative to [35 S]-methionine for the detection of nascent protein synthesis.