Sodium Hydroxymethylglycinate

What is it? “Sodium hydroxymethylglycinate is an organic compound derived from the amino acid glycine.” (source) It is primarily used as a preservative ingredient; it is a formaldehyde donor, meaning it slowly releases very small amounts of formaldehyde to prevent microbial growth.

It is sold under several trade names, including:

Sodium Hydroxymethylglycinate is usually sold as a 50% solution with water, but always double check the concentration and usage rate for what you have.

Different suppliers describe its efficacy and broad-spectrum-ness in a variety of ways.

  • “This single preservative is cost-effective and provides broad spectrum protection against Gram-positive bacteria, Gram-negative bacteria, yeast and mold.” (Ashland)
  • “Broad spectrum covereage can be obtained by combining [Sodium Hydroxymethylglycinate] with Paraben blends such as Phenochem or Sharomix 824.” (Sharomix HMG)
  • “It acts on its own on a relatively broad spectrum of microbes and bacteria of all kinds.” (Spec-Chem Industry Inc.)
  • “Active against moulds and bacteria and least active against yeast.” (New Directions Aromatics Australia)

As of April 2025 I haven’t worked with this ingredient so I have no hands-on experience to share.
INCI

Sodium Hydroxymethylglycinate
Appearance

Clear liquid
Usage rate

I’ve found a variety of usage rates.

  • The low end usually ranges from 0.2–0.5%
  • The high end ranges from 0.5–1%

Defer to your supplier for the product you have.
Scent

“Mild characteristic odor”
pH

10–12
Effective pH

3.5–12
Solubility

Water soluble
Why do we use it in formulations?

Sodium Hydroxymethylglycinate is primarily used as a preservative, but it will also raise the pH of formulations, can be used to neutralize anionic thickeners like Acrylates/C10-30 Alkyl Acrylate Crosspolymer, and has some hair conditioning benefits.
Do you need it?

No; there are plenty of other easier-to-get preservative options.
Refined or unrefined?

This ingredient only exists as a refined product.
Strengths

It’s a relatively rare preservative that can work in high pH environments, and it’s fully water soluble.
Weaknesses

It’s not widely available.
Alternatives & Substitutions

Liquid Germall™ Plus is an easy to use, fully water soluble broad spectrum preservative with a broad effective pH range; it would be my first choice.
How to Work with It

Add to formulations once they are below 60°C. Sodium Hydroxymethylglycinate will raise the pH of formulations, so be sure to test & adjust after adding it.
Storage & Shelf Life

Stored somewhere cool, dark, and dry, the shelf life is 1 year from the date of manufacture.
Tips, Tricks, and Quirks

From New Directions Aromatics Australia: “Should not be used when using Citrus Essential Oils – it will turn the product PINK.”

“This product can be used to neutralize anionic thickening polymers, such as carbomer.” (Ashland)
Recommended starter amount

15g (0.5 oz)
Where to Buy it

Buy it from an online DIY ingredient supplier; I’ve only found it at New Directions Aromatics Australia.

Want to learn more about preservatives and compare them? Check out this chart!

Some Formulations that Use Sodium Hydroxymethylglycinate

Originally published on April 8, 2025