No serious systemic ghk-cu side effects have been documented in peer-reviewed human studies at therapeutic doses
Aoyama and Nakaki describe glutathione as a redox buffer and antioxidant-system component in cellular redox homeostasis [5]
A previous study also reported a similar low random reactivity of selected reactive electrophiles 32
These processes yield hydrolysates containing whole proteins, peptides of varying sizes, and free amino acids
However, if you have a sensitive stomach, taking it with a small amount of food is perfectly fine and can help prevent mild digestive discomfort
Khatun et al., An All-Oral Antiviral Combination Strategy against COVID-19 Enabled by the Synergistic Mechanism of Action of Auranofin and Remdesivir, Elsevier BV, doi:10.2139/ssrn.6942990