Taking glutathione long-term has been linked to lower zinc levels. Inhaled glutathione may also trigger asthma attacks in people who have asthma. Symptoms may include wheezing. Avoid taking glutathione if you're sensitive to it. Experts don't know if taking glutathione is safe during pregnancy and while breastfeeding. Tell your doctor about any supplements you're taking, even if they're natural. That way, your doctor can check on any potential side effects or interactions with any medications. Supplements are not regulated by the FDA.