Glutathione vs NAD+: evidence, cost, and legality

Which is better, glutathione or NAD+?

Both are graded human RCT on the strength of oral supplement trials, both injectables are compounded under FDA's interim policy for nominated bulk substances, and neither is a prohibited substance in sport. NAD+ precursors have the one metabolic finding (about 25% better muscle insulin sensitivity with NMN in 25 prediabetic women), while glutathione has the longer trial (6 months, 54 adults) showing sustained increases in body stores and immune cell activity. For intravenous use of either, there is no randomized evidence of benefit, and FDA has warned about endotoxin contamination in compounded glutathione. [1] [2] [3] [4] [5] [8] [9]

How do glutathione and NAD+ compare?

Glutathione and NAD+ compared by dimension
Dimension	Glutathione	NAD+
What it is [1] [7]	A tripeptide (glutamate, cysteine, glycine) and the main intracellular antioxidant.	A coenzyme (a dinucleotide, not a peptide) for energy metabolism and a substrate for sirtuins, PARP, and CD38.
Main randomized trial result [1] [2] [3] [4]	Oral 1,000 mg per day for 6 months raised whole blood glutathione about 30% and lymphocyte glutathione about 35%, and doubled natural killer cell activity at 3 months (54 adults). A 4 week trial of 500 mg twice daily found no change.	NR 1,000 mg per day raised blood NAD+ about 60% in 24 older adults; NMN 250 mg per day improved muscle insulin sensitivity about 25% in 25 prediabetic women, without changes in weight or fasting glucose.
Negative or null findings [2] [6]	No change in oxidative stress biomarkers in the 4 week trial; skin lightening trials are small and inconsistent.	A 2025 meta-analysis found no effect of NR or NMN on muscle mass or physical function.
Intravenous evidence [1] [5]	No published randomized trial of IV glutathione for any common clinic indication.	One 11 person pharmacokinetic pilot of a 6 hour infusion with no clinical endpoints; plasma NAD+ lagged and metabolites were excreted in urine.
Safety signals [1] [3] [5] [9]	Oral forms well tolerated; FDA has warned about compounded injectable glutathione with high endotoxin causing fever and chills, and about injections marketed for skin lightening.	Oral precursors well tolerated; IV infusions commonly cause chest pressure, nausea, cramping, and flushing when run quickly.
Regulatory status [8] [9]	Oral: dietary supplement. Injectable: nominated 503A bulk substance compounded under FDA's interim enforcement policy where state boards permit.	Oral NR and NMN: dietary supplements (FDA has questioned NMN's status as a dietary ingredient). Injectable: nominated 503A bulk substance compounded under the same interim policy.
Theoretical interactions [1] [7]	May blunt chemotherapy that works through oxidative stress; oncology patients need their oncologist's input.	Is the substrate of PARP inhibitors used in oncology; the interaction has not been tested.
Typical cost [8]	Oral roughly 20 to 50 USD per month; IV 100 to 300 USD per infusion; compounded injections roughly 100 to 250 USD per month.	Oral NR or NMN roughly 30 to 100 USD per month; IV 300 to 1,000 USD per session; compounded injections roughly 150 to 400 USD per month.

Evidence grade and regulatory status

Pulled from each peptide’s own record, so it stays in step with the peptide pages.

Glutathione and NAD+: grade, status, and cost
Attribute	Glutathione	NAD+
Class	Naturally occurring tripeptide (glutamate, cysteine, glycine), the main intracellular antioxidant; sold as oral supplements and compounded injections	Coenzyme (a dinucleotide, not a peptide) central to redox metabolism and sirtuin and PARP signaling; sold as intravenous or subcutaneous NAD+ and as oral precursors
What it is	The body's main antioxidant tripeptide; one RCT shows oral doses raise body stores, clinical benefit is unproven, and IV use is compounded pending an FDA rule.	A coenzyme, not a peptide, whose precursors raise blood NAD+ in human RCTs; clinical benefits and IV NAD+ itself remain largely unproven.
Evidence	Evidence: Human RCT evidence	Evidence: Human RCT evidence
FDA status	Regulatory: Under FDA review	Regulatory: Under FDA review
Compounding	Glutathione is not an FDA approved drug. Oral glutathione is sold lawfully as a dietary supplement. Injectable glutathione is compounded from a bulk substance that was nominated for the FDA 503A bulks list and appears on the nominated substances lists pending a final determination; compounding continues under FDA's interim enforcement policy where state boards permit. FDA has issued warnings about compounded glutathione products containing high levels of endotoxin and about glutathione injections marketed for skin lightening, which is not an approved use.	NAD+ (nicotinamide adenine dinucleotide) is not an FDA approved drug. It was nominated for the FDA 503A bulks list and appears on the nominated substances lists pending FDA evaluation; no final rule placing it on or excluding it from the bulks list had been published as of the last verification date, so compounded NAD+ injections and infusions are dispensed under FDA's interim enforcement policy where state boards permit. Oral NR and NMN are sold as dietary supplements, and FDA has questioned whether NMN qualifies as a dietary ingredient because of prior drug investigation.
WADA	WADA: Not WADA prohibited	WADA: Not WADA prohibited
Routes	Oral capsule, liposomal, or sublingual (dietary supplement), Intravenous infusion or push (compounded, clinics), Intramuscular or subcutaneous injection (compounded), Inhaled (nebulized, studied in cystic fibrosis)	Oral precursors: nicotinamide riboside, nicotinamide mononucleotide (dietary supplements), Intravenous infusion of NAD+ (clinics, compounded), Subcutaneous or intramuscular NAD+ injection (compounded), Intranasal and transdermal products exist without absorption data
Typical cost	Compounded injectable glutathione through licensed telehealth programs runs about 75 to 100 USD per month; a glutathione injection or IV add-on at an IV clinic is about 35 to 50 USD. Oral supplements are sold over the counter. Prices checked 2026-09-22 on published provider and pharmacy price pages.	IV NAD+ at a published clinic menu costs about 450 to 900 USD per session for 500 to 1,000 mg (member prices from 400 USD); compounded subcutaneous NAD+ through telehealth is about 79 to 199 USD per month. Oral NR or NMN supplements are sold over the counter. Prices checked 2026-09-22 on published provider and pharmacy price pages.
Last verified	Sep 22, 2026	Sep 23, 2026

Has glutathione been tested directly against NAD+?

No published trial has compared glutathione and NAD+ directly. The dimensions above come from separate studies and labels, and cross-trial comparisons are less reliable than a direct trial.

What do glutathione and NAD+ cost?

Typical cost of Glutathione and NAD+
Dimension	Glutathione	NAD+
Typical cost	$75 to $100 per month	$79 to $199 per month
Price detail	Glutathione price by channel	NAD+ price by channel

Where a price index exists, the range is the cash price per month across branded, compounded, and telehealth channels, without insurance. The cost pages give each channel separately with its sources. Otherwise the typical cost from the peptide record is shown. Legal access depends on your state: see peptide legality by state.

Frequently asked questions

Should I take glutathione or NAD+?

It depends on the goal, and neither has proven clinical benefits. Oral glutathione raised body glutathione and natural killer cell activity over 6 months. Oral NAD+ precursors raised blood NAD+, and NMN improved muscle insulin sensitivity in prediabetic women. Neither trial measured symptoms, disease, or aging outcomes. [1] [3] [4]

Are IV drips of either one proven?

No. There is no randomized trial of IV glutathione for common clinic uses, and the only IV NAD+ study was an 11 person pharmacokinetic pilot without clinical endpoints. The randomized evidence for both is for oral forms. [1] [5]

Does oral glutathione get absorbed?

The 6 month trial found that daily oral glutathione raised levels in blood, red cells, lymphocytes, and buccal cells in a dose dependent way, but a 4 week trial found no change, so sustained dosing appears necessary. Levels returned to baseline within a month of stopping. [1] [2]

Are compounded glutathione and NAD+ injections legal?

Both are nominated bulk substances that 503A pharmacies may compound under FDA's interim enforcement policy where state boards allow, pending FDA's final decision. FDA has warned about endotoxin contamination in some compounded glutathione products. [8] [9]

Can athletes use them?

Neither substance is prohibited, but WADA method M2 prohibits intravenous infusions or injections above 100 mL per 12 hour period outside legitimate hospital care, which can apply to IV drips of either. [10]

Conditions studied

Sources

Numbered citations above point to these primary sources. PubMed entries link to the indexed abstract.

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APA style: PeptideAgent. (2026, September 22). Glutathione vs NAD+: evidence, cost, and legality. https://peptideagent.ai/compare/glutathione-vs-nad-plus
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Glutathione vs NAD+

The short answer