glutathione 200 mg/ml Glutathione-L Injection Glutathione 200mg/mL - 30mL Vial:
Description
But it may also indicate liver or bile duct problems, according to Mayo Clinic

The MHRA advises following current clinical guidelines, and it signposts to the NICE Clinical Knowledge Summary (CKS) on this topic (NICE, 2022)

What are Substances of Abuse

Add 3.0 mL bacteriostatic water to one 100 mg vial ~33.3 mg/mL , a concentration that keeps small doses on readable U-100 marks

You can also take glutathione via inhalation or injection

[4] Sikiric, P., Seiwerth, S., Brcic, L., & Kolenc, D
