Glutathione Side Effects: Oral, IV and Injection Risks (2026)

[Nelson Vergel]

By Nelson Vergel, Founder, ExcelMale.com | Updated November 2026

ExcelMale Consensus: Oral glutathione has a mild side-effect profile. Bloating, cramps and loose stools are the usual complaints. The real risks sit with IV and injectable glutathione, where contaminated ingredients have caused fever, shock-like reactions and hospitalizations, and with inhaled glutathione in people with asthma.

What you'll learn

• Side effects by route: oral, IV or injection, inhaled
• The FDA warnings on contaminated injectable glutathione (2019 and 2026)
• Who should avoid glutathione
• Whether oral glutathione raises your levels at all

What Are the Side Effects of Glutathione?​

Most side effects of oral glutathione are digestive. People report bloating, abdominal cramps, loose stools and, less often, skin rash. In a study of healthy adults taking 500 mg twice daily for four weeks, no serious side effects were reported (Drugs.com summary). Injectable and IV glutathione carry more serious risks, covered below. Long-term safety data beyond six months is thin for every route.

Route	Common side effects	Serious risks
Oral or liposomal	Bloating, cramps, loose stools, rash	None reported in trials up to 6 months
IV or IM injection	Injection-site soreness, bruising	Endotoxin reactions from contaminated product; one report of reversible liver toxicity at 1,200 mg/day IV for a month
Inhaled (nebulized)	Cough	Bronchial spasm and shortness of breath, mainly in asthma

Is Oral Glutathione Safe Long Term?​

Oral glutathione appears safe for at least six months at 250 to 1,000 mg per day. The best data comes from a 2015 randomized, double-blind trial in 54 healthy adults by Richie and colleagues at Penn State, published in the European Journal of Nutrition. Nobody has studied daily use over several years.
One theoretical concern: long-term glutathione use may lower zinc levels. No controlled trial has measured this. If you take glutathione for months, check zinc on your next blood panel.

What Are the Dangers of Glutathione Injections and IV Drips?​

The main danger is contamination. Compounders sometimes use glutathione powder sold as a dietary supplement, which is not made for sterile injection and can carry high levels of bacterial endotoxin.
FDA has warned about this twice:

• 2019: FDA received reports of seven patients who had adverse events after IV glutathione made from Letco Medical powder, from nausea and vomiting to breathing trouble that required hospitalization (FDA).
• August 27, 2026: FDA reported at least 30 patients with fever, chills, dizziness, signs of shock and sepsis-like symptoms after IV glutathione made with supplement-grade powder from Medisca. Some were hospitalized, and two Texas pharmacies recalled their products (FDA).

If you use injectable glutathione, ask your prescriber or pharmacy where their glutathione powder comes from. It should be pharmaceutical grade made for sterile compounding, not a supplement-grade ingredient. Report any reaction to FDA MedWatch.
IV glutathione is also marketed for skin lightening. No randomized trial has shown it works for that purpose.

Can Glutathione Cause Breathing Problems?​

Yes, mainly when inhaled. Nebulized glutathione has been linked to bronchial spasm, cough and shortness of breath. If you have asthma, avoid inhaled glutathione and talk to your doctor before taking high oral doses.

Who Should Avoid Glutathione?​

• People with asthma (inhaled forms especially)
• Pregnant or breastfeeding women, since no safety data exists
• Anyone considering IV glutathione from a clinic that cannot name its ingredient source
• People with liver or kidney disease, unless their doctor approves it

Does Oral Glutathione Raise Your Levels?​

Yes, slowly. In the Richie trial, 1,000 mg per day raised glutathione in red blood cells, plasma and lymphocytes by 30 to 35% at six months. Levels returned to baseline one month after stopping. Many members prefer to raise glutathione with its building blocks, NAC and glycine, which costs less. Some members report that NAC raised their hematocrit, so men on TRT should watch that number.

Frequently Asked Questions​

Is it safe to take glutathione every day?
Daily oral doses up to 1,000 mg were well tolerated for six months in a controlled trial. Longer-term data does not exist.
What happens if you take too much glutathione?
With oral forms, expect digestive upset. With IV forms, very high daily doses have been linked to reversible liver injury in one report.
Is liposomal glutathione safer than regular oral glutathione?
Both are oral, so their side effects are similar. Liposomal forms are marketed for better absorption.
Does glutathione interact with TRT?
No direct interaction is known. If you take NAC to raise glutathione, track hematocrit on your labs.

Related ExcelMale Threads​

• Can Oral Glutathione Supplements Work?
• Benefits of Glycine Supplementation
• NAC Side Effects
• How to Read Your TRT Blood Panel

Discuss your experience in the ExcelMale forum.
This article is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting or modifying any hormone therapy or medical treatment.