Glabridin Supplier Evaluation: What Can Purity, COA and Activity Data Tell You?

Two Glabridin suppliers quote different grades for the same brightening serum. One offers 90% purity, the other 40%. Both provide a COA, although the specifications say little about how the materials behave in a finished formula.

The price difference is easy to see. Comparing the actual Glabridin content takes a little more work, particularly when the grades use different solvents or contain other licorice constituents.

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Glabridin

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The first thing to establish is what each supplier is selling.

Comparing Glabridin Grades

Glabridin (CAS 59870-68-7) is an isoflavan found in licorice. Its activity against pigmentation-related pathways has attracted interest in cosmetic formulation.

Huatai Bio-Fine’s 2026 catalogue describes several commercial grades.

The two 90% variants have different formulation requirements and should be assessed individually.

Take a serum formulated to contain 0.05% actual Glabridin. The theoretical additions are:

These figures assume that assay percentages represent Glabridin by weight.

With the 40% material, approximately 0.075% of the finished formula comes from other constituents. The corresponding figure for the 90% material is only 0.0056%.

That difference may affect the formula, depending on what those constituents are. A standardized licorice extract and a formulated Glabridin dispersion should not be treated as interchangeable simply because both state an assay percentage.

For a clear aqueous serum, I would want to examine the composition of the water-compatible grade before running a trial. An oil-compatible powder could be a reasonable option for a facial oil or emulsion, provided it dissolves at the intended concentration.

A 90% COA Still Needs a Closer Look

Imagine two certificates reporting 90% Glabridin by HPLC.

The first provides a quantitative assay using a reference standard. The second reports chromatographic peak-area purity, without explaining the calculation.

Those results may describe different things.

Peak-area percentage does not automatically establish that 90% of the powder’s weight is Glabridin. The method, calibration and reporting basis determine how the result should be interpreted.

For supplier qualification, I would check the following information.

A COA may refer to separate supporting test reports. Those documents can be requested when the information is not included directly.

There is another reason to examine the complete specification. Two batches with similar assay results may show different dissolution behavior. Particle size and the composition of the remaining material are possible factors worth investigating.

The assay alone would not explain such a difference.

What Can Activity Studies Tell a Formulator?

The frequently cited work by Yokota et al. (1998) examined Glabridin in B16 mouse melanoma cells and guinea pig skin.

In the cell experiments, tyrosinase activity was inhibited at concentrations of 0.1-1.0 micrograms/mL. Topical application of 0.5% Glabridin also reduced UVB-induced pigmentation and erythema in guinea pigs.

These results help explain the interest in Glabridin for pigmentation-related skincare.

They leave an important formulation question open. How much of the Glabridin added to a finished product remains available under the conditions of use?

A cell-culture concentration tells us little about dissolution in a serum. Nor does a result obtained on guinea pig skin establish the performance of a commercial cosmetic on human skin.

Huatai’s catalogue includes micronization and stability observations for its 90% Glabridin grade. It also presents images from a UV-induced pigmentation experiment using a 3D skin model.

The catalogue offers a starting point for technical discussion, although the available presentation does not provide sufficient experimental detail to independently calculate the treatment effect.

For a formulation trial, comparing grades at the same actual Glabridin concentration would be more informative than using the same percentage of raw material.

Storage observations should cover precipitation and appearance, followed by analytical measurement of Glabridin retention. A formula that looks unchanged may still show a reduction in measured active content.

Regulatory Considerations

Cosmetic use in the EU falls under Regulation (EC) No 1223/2009. Article 10 requires a safety assessment of the finished cosmetic product, and applicable ingredient restrictions must be reviewed.

The European Commission’s CosIng database is useful for ingredient information. An entry there does not establish approval for cosmetic use.

For Glabridin, the review should account for the supplied grade and its composition. Documentation for a high-purity powder may differ from that required to assess a formulated grade containing additional components.

FAQ: Glabridin Supplier Questions

1. What is Glabridin used for in skincare?

Glabridin is studied for pigmentation-related activity, including effects on tyrosinase, and for anti-inflammatory properties.

2. How do I find a reliable Glabridin supplier?

Compare actual grade specifications and batch COAs. Ask for analytical methods, sample material and information about manufacturing consistency.

3. Is 90% Glabridin better than 40%?

It supplies more active Glabridin per gram. Whether it is the better choice depends partly on the other constituents and the intended formulation.

4. Is Glabridin water-soluble?

Pure Glabridin has limited water solubility. Commercial water-compatible grades may use carriers or other formulation components.

5. What should a Glabridin COA include?

The batch identity, assay, identification and relevant quality results. Buyers should also be able to review the testing methods.

6. What concentration of Glabridin is suitable for skincare?

There is no single level suitable for every product. The grade, target active concentration, stability and safety assessment all influence the decision.

7. Can tyrosinase inhibition data support cosmetic claims?

It provides evidence of biological activity under the test conditions. Finished-product claims require evidence appropriate to the product and the claim.

8. Where can I source Glabridin for cosmetic manufacturing?

Huatai Bio-Fine supplies different Glabridin grades. Technical specifications, samples and relevant quality documents can be requested for evaluation.

References

1. Yokota T. et al. (1998). The Inhibitory Effect of Glabridin from Licorice Extracts on Melanogenesis and Inflammation. Pigment Cell Research, 11(6), 355-361. DOI: 10.1111/j.1600-0749.1998.tb00494.x.
2. European Parliament and Council. Regulation (EC) No 1223/2009 on Cosmetic Products.
3. European Commission. CosIng Cosmetic Ingredient Database.
4. Huatai Bio-Fine Chemical Co., Ltd. (2026). In-cosmetics Ingredient Catalogue, pp. 3-4.