Why Cold-Chain Shipping Matters for NAD+ and Glutathione Nasal Sprays (And What Happens When Liquid NAD+ Ships Warm)

Liquid NAD+ and reduced glutathione are both sensitive to warmth over time. Lab studies show that warmer storage speeds up the chemical changes that turn each one into a less useful form. That is why our NAD+ Nasal Spray and Glutathione Nasal Spray ship cold, packed with cold packs in an insulated box, and why we ask you to keep them in the fridge. This guide explains what cold-chain shipping means, what the research shows about warm storage, and what to do when your order arrives.

Key Takeaways

• In a 2024 lab study of nicotinamide cofactors in solution, a small rise in temperature made a significant difference to long-term stability.
• Reduced glutathione in solution slowly oxidizes to its used form. In one set of stability tests, a solution at room temperature lost about 10 to 12 percent a month, while a refrigerated one showed no measurable loss over four months.
• Our NAD+, Glutathione and Clarity nasal sprays ship cold, Monday to Thursday, so packages are not left sitting in a warehouse over a weekend.
• Put cold-shipped sprays in the fridge when they arrive, and do not freeze them.
• When you compare brands, ask how they ship, what they tell you about storage and what happens if an order arrives warm.

What Cold-Chain Shipping Means for a Nasal Spray

Cold chain simply means keeping a product cool from the time it is packed until it reaches your fridge. For our cold-shipped sprays, that means:

• Each order is packed in an insulated foam box with cold packs, with a sticker on the outside of the box.
• Cold orders go out Monday to Thursday, so a package is not left in a depot over a weekend.
• Every order ships 2nd Day Air, which keeps time in transit short.
• Each bottle carries storage directions, and our guarantee and order help form covers orders that arrive damaged or warm.

Cold shipping costs more than a padded mailer, but it protects what you paid for. You can read our shipping details on the Orders and Shipping page.

What Happens to Liquid NAD+ When It Gets Warm

NAD+ and its partner molecule NADH carry energy in every cell. Outside the body, in water, both slowly break down. A 2024 study in the journal Molecules tracked these cofactors in three common lab buffers at 19 °C and 25 °C for up to 43 days. The authors found that a mild temperature increase was significant for long-term stability. In the most stable buffer, NADH lost less than 10 percent over 43 days at 19 °C but about 25 percent at 25 °C (Wolfe et al., 2024).

Lab buffers are not the same as a finished nasal spray, and every formula behaves a little differently. The direction is consistent, though: the warmer a liquid cofactor sits, and the longer it sits there, the faster it changes. That is the reason we keep NAD+ cold from our bench to your fridge, and why our guide Does NAD+ nasal spray need refrigeration? tells you to follow the storage directions on your bottle.

Why Glutathione Is Shipped Cold Too

Glutathione comes in two forms: the active, reduced form (GSH) and the used, oxidized form (GSSG). Your cells use an enzyme to turn the used form back into the active one (Couto et al., 2016). In a bottle, there is no enzyme to do that, so the goal is to keep the active form from oxidizing in the first place.

A U.S. patent on storing reduced glutathione solutions describes this oxidation as gradual, and notes it proceeds in water even without catalysts. In its stability tests, a solution held at 25 °C fell to about 90 percent of its starting active glutathione within three weeks, a loss of about 10 to 12 percent a month. A matching solution held at 5 °C showed no decrease beyond measurement error over four months (US Patent 6,835,811). More on the molecule itself is in our glutathione ingredient guide.

Warm vs Cold Storage at a Glance

What to Do When Your Order Arrives

1. Open the box the day it arrives and move the NAD+ and Glutathione bottles to the fridge.
2. Keep the cap on between uses.
3. Take it out to use it, then put it back. A few minutes on the counter each day is part of normal use.
4. If the box arrives warm or damaged, take a photo and use our order help form so we can make it right.
5. Travelling? Our guide on travelling with NAD+ nasal spray covers short trips.

Which of Our Sprays Ship Cold

Three of our sprays ship cold: NAD+ Nasal Spray, Glutathione Nasal Spray and Clarity Nasal Spray. Our other sprays, including Methyl B-12, Melatonin, Theanine and Kanna, ship without cold packs. Follow the storage directions on each bottle. If you use several of these together, our NAD+ vs glutathione guide explains how they differ.

How to Check Whether a Brand Takes Cold Chain Seriously

• Does it ship liquid NAD+ or glutathione with cold packs in an insulated box?
• Does it avoid shipping cold products over a weekend?
• Does the bottle carry clear storage directions?
• Will it replace an order that arrives warm?
• Does it use third-party tested ingredients and show you its label?

Every one of our sprays is made with third-party tested ingredients and formulated in-house. Use code SPRAY20 at checkout for 20% off NAD+ Nasal Spray.

Frequently Asked Questions

Why is NAD+ nasal spray shipped cold?

Liquid NAD+ changes faster when it is warm. Lab research shows that even a mild temperature rise affects the long-term stability of nicotinamide cofactors in solution, so we ship it cold and ask you to refrigerate it.

What happens if liquid NAD+ ships warm?

Warmth speeds up the chemical changes that break NAD+ and NADH down. A short time warm is not the same as weeks warm, but the longer and hotter, the greater the change. If your order arrives warm, contact us.

Does glutathione nasal spray need to be refrigerated?

Ours ships cold and should be kept in the fridge. Reduced glutathione in solution slowly oxidizes, and stability tests show refrigeration slows that change a great deal.

Can I freeze my NAD+ or glutathione spray?

No. Keep them refrigerated, not frozen.

Which Synchronicity sprays ship cold?

NAD+ Nasal Spray, Glutathione Nasal Spray and Clarity Nasal Spray ship cold. The rest ship without cold packs.

Why do cold orders only ship Monday to Thursday?

So a cold package is not left in a carrier's warehouse over a weekend.

What should I do if my order arrives warm?

Take a photo of the package and contents and send it through our guarantee and order help form. We will look after it.

How long can I leave the bottle out of the fridge?

Use it and return it to the fridge. Short daily handling is part of normal use; avoid leaving it in a hot car or bag.

This article is for education only and is not medical advice. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk with a qualified healthcare provider before starting a new supplement, especially if you are pregnant, nursing, take medication or manage a health condition.

Sources

1. Wolfe KD, et al. Long-Term Stability of Nicotinamide Cofactors in Common Aqueous Buffers: Implications for Cell-Free Biocatalysis. Molecules, 2024. https://pubmed.ncbi.nlm.nih.gov/39598842/
2. Couto N, Wood J, Barber J. The role of glutathione reductase and related enzymes on cellular redox homoeostasis network. Free Radical Biology and Medicine, 2016. https://pubmed.ncbi.nlm.nih.gov/26923386/
3. US Patent 6,835,811 B1. Extended storage of reduced glutathione solutions, 2004. https://patents.google.com/patent/US6835811B1/en