What Is Menthyl Lactate?
Menthyl lactate, CAS 59259-38-0, is a cooling agent (also called a coolant or freshness agent) made by esterifying menthol with lactic acid. It produces a mild, long-lasting cooling sensation with a weak odour – the feature that distinguishes it from menthol itself, which is intensely minty and volatile.
Because it cools strongly but smells only faintly, menthyl lactate is used where a product should feel cool without a dominant mint flavour: oral care, confectionery and chewing gum, cosmetics and personal care, and flavour/fragrance blends. This guide covers the chemistry, specification, properties, production, cooling mechanism and applications of menthyl lactate, its comparison with menthol and other coolants, dosage, quality and regulatory points, and supply.
| CAS number | 59259-38-0 |
| Chemical name | Menthyl lactate ((1R,2S,5R)-2-isopropyl-5-methylcyclohexyl lactate) |
| Synonyms | Menthyl lactate; lactic acid menthyl ester; menthol lactate; coolant ML |
| Molecular formula | C13H24O3 |
| Molecular weight | 228.33 g/mol |
| Appearance | White crystalline solid |
Chemistry and Structure
Menthyl lactate is an ester: the hydroxyl group of menthol is joined to the carboxyl group of lactic acid, releasing water:
Menthol + Lactic acid -> Menthyl lactate + H2O
The molecule therefore has two parts, and each contributes something useful:
- The menthyl part (from menthol) provides the cooling character – the structure that interacts with the cold-sensing receptor.
- The lactate part (from lactic acid) shifts the physical behaviour: the ester is a higher-melting, less volatile solid with a much weaker odour than menthol.
- The ester linkage means there is no free menthol hydroxyl; combined with the higher molecular weight, this is why menthyl lactate is far less odorous and less volatile than menthol while still cooling.
This is the essence of the “coolant” concept: take the cooling part of menthol, but mute the odour and slow the release.
Specifications
Menthyl lactate is supplied as a white crystalline solid to the following specification:
| Parameter | Specification |
|---|---|
| Colour and appearance | White crystalline solid |
| Odour | Weak, crown-daisy- or tobacco-like aroma |
| Purity | 98.0% min |
| Acid value | 2.0 max |
| Melting point | 40.0 °C min |
| Parameter | What it controls |
|---|---|
| Purity (98.0% min) | Content of the ester; a low value means residual menthol/lactic acid or by-products |
| Acid value (2.0 max) | Residual free acidity (unreacted lactic acid); affects odour, stability and skin feel |
| Melting point (40.0 °C min) | Identity and purity of the crystalline solid |
| Odour (weak) | The key sensory requirement for a low-odour coolant |
A specification sheet and a per-batch certificate of analysis (COA) are available on request.
Physical and Chemical Properties
| Property | Value / behaviour |
|---|---|
| Form | White crystalline solid |
| Molecular weight | 228.33 g/mol |
| Melting point | About 40 °C and above |
| Odour | Weak (crown-daisy/tobacco-like) – much lower than menthol |
| Volatility | Low compared with menthol (higher molecular weight ester) |
| Solubility | Lipophilic ester; soluble in oils, alcohols and typical flavour/cosmetic solvents |
| Stability | Stable in normal storage; the ester can hydrolyse under strong acid/base or prolonged high heat |
Two properties matter most for formulation: the low odour (so it does not clash with a flavour) and the slow, mild cooling (so the effect lasts longer than the sharp menthol hit).
How Menthyl Lactate Is Produced
Menthyl lactate is made by the acid-catalysed esterification of menthol with lactic acid:
- Esterification – menthol and lactic acid are heated together with an acid catalyst; water is removed to drive the equilibrium toward the ester.
- Neutralisation and washing – the catalyst is neutralised and the crude ester is washed to remove residual acid.
- Purification – the product is distilled or crystallised to the required purity and acid value.
- Finishing – the purified menthyl lactate is flaked or milled to the crystalline solid.
The acid value on the specification is the direct result of this process: it measures the free lactic acid left after esterification, so good neutralisation and purification keep it low. The menthol used is typically L-menthol, which is why the product carries menthol’s cooling character.
The Cooling Effect: Sensory Basis
Menthyl lactate produces the sensation of coolness by the same sensory route as menthol – activation of the TRPM8 cold-sensing receptor – but the effect is milder and longer-lasting, with far less odour.
| Feature | Menthol | Menthyl lactate |
|---|---|---|
| Cooling intensity | Strong, sharp | Mild, smooth |
| Duration | Shorter (volatile) | Longer (less volatile) |
| Odour | Strong mint | Weak |
| Best used for | Where the mint note is wanted | Where cooling is wanted without odour |
This is a sensory property of the ingredient, not a medical effect; it is why menthyl lactate is described as a “coolant” or “freshness agent”. (This page is not medical advice.)
Menthyl Lactate vs Menthol and Other Coolants
| Coolant | CAS | Type | Odour | Cooling | Typical use |
|---|---|---|---|---|---|
| Menthyl lactate | 59259-38-0 | Menthol-lactic acid ester | Weak | Mild, long-lasting | Oral care, confectionery, personal care |
| L-Menthol | 2216-51-5 | Monoterpene alcohol | Strong mint | Strong, sharp | Mint flavour + cooling |
| WS-type coolants (menthyl/menthane derivatives) | varies | Synthetic cooling agents | Low to none | Strong, tunable | Where strong cooling with low odour is wanted |
| Peppermint oil | – | Essential oil | Complex mint | Moderate | Where the full oil aroma is wanted |
Guidance: choose menthyl lactate where a smooth, long cooling effect with little odour is wanted; choose L-menthol where the mint note matters; choose a WS-type coolant where the strongest possible cooling with minimal odour is needed. Coolants are frequently blended to tune the cooling curve.
Applications by Industry
| Industry | Role of menthyl lactate |
|---|---|
| Oral care | Long-lasting cooling feel in toothpaste, mouthwash and oral rinse |
| Confectionery | Smooth cooling in chewing gum, mints and candy |
| Cosmetics / personal care | Refreshing cooling sensation in skin, hair and shaving products |
| Flavour / fragrance | A low-odour cooling component in blends |
- Oral care – menthyl lactate adds a fresh, cooling feel that lingers, without overpowering the toothpaste or mouthwash flavour.
- Confectionery and gum – it gives a smooth, prolonged cooling effect, often blended with menthol or WS coolants.
- Cosmetics and personal care – used for a refreshing, long-lasting cooling sensation in skin and hair products.
Dosage and Formulation Notes
| Application | Starting-point guidance |
|---|---|
| Oral care | A small fraction of a percent, set by the required cooling and taste |
| Confectionery / gum | Set by the flavour and the desired cooling curve |
| Personal care | Very low levels, set by the cooling sensation and skin feel |
| Blends | Combined with menthol and/or WS coolants to tune intensity and duration |
Menthyl lactate is a crystalline solid, so it is dissolved in an appropriate solvent or flavour base before use. Because it is mild, it is often blended rather than used alone. Confirm the level by sensory evaluation and stability testing on your own formulation.
Quality, Standards and Regulatory
| Point | Note |
|---|---|
| Identity/purity | Confirmed by purity, acid value and melting point on the COA |
| Cosmetic/flavour use | Where used in cosmetics or as a flavouring, confirm the permitted use for your market |
| Origin | An ester of menthol and lactic acid; both are established flavour/cosmetic materials |
Always confirm the grade and the permitted use for your application and market before ordering.
Safety, Handling and Storage
- Low hazard – menthyl lactate is a mild ester, but it is a sensory active and should be handled with normal care.
- Dust – avoid breathing the powder; use ventilation where large amounts are handled.
- Storage – keep sealed, cool and dry, away from heat and strong odours; as a solid ester it should stay free-flowing and odour-stable.
- Hydrolysis – avoid prolonged contact with strong acids/bases and high heat, which can hydrolyse the ester.
Packaging, Logistics and Supply
| Item | Standard options |
|---|---|
| Packaging | 25 kg fibre drums or as agreed |
| Documentation | Per-batch COA and SDS |
| Incoterms | FOB and CIF |
| Storage | Sealed, cool and dry |
Menthyl lactate price tracks the menthol feedstock (itself harvest-linked) and lactic acid, plus the energy of esterification and purification. Because the menthol input is seasonal, menthyl lactate pricing also shows some seasonality. Buying on committed tonnage gives the best terms.
Cooling Curves and Why Blending Matters
Coolants differ not only in strength but in the shape of the cooling they deliver: how quickly it comes on (onset), how strong it is (intensity) and how long it lasts (duration).
| Coolant | Onset | Intensity | Duration |
|---|---|---|---|
| Menthol | Fast | Strong | Short |
| Menthyl lactate | Slower | Mild | Long |
| WS-type coolants | Fast | Strong | Medium-long |
Because of this, formulators usually blend coolants: a fast, strong component (menthol or a WS coolant) gives an immediate hit, while menthyl lactate extends a smooth cooling tail and reduces the total odour. The blend is tuned so the product cools the way the flavour and the consumer expect – for example, a sharp initial freshness followed by a long, gentle cool.
Menthyl Lactate in Oral Care and Gum
| Product | Role of menthyl lactate |
|---|---|
| Toothpaste | A lingering cooling feel without overpowering the flavour |
| Mouthwash | Smooth, low-odour cooling rinse |
| Chewing gum | A cool effect that lasts through chewing |
| Mints and candy | A gentle, long cooling finish |
In oral care the low odour is the decisive advantage: the flavourist can build a fruit, tea or other flavour and still add a cooling feel, because menthyl lactate contributes coolness without insisting on a mint note. It is often paired with menthol (for the immediate hit) and a WS coolant (for extra intensity).
Menthyl Lactate in Cosmetics and Skin Care
| Category | Role of menthyl lactate |
|---|---|
| Skin care | Long-lasting cooling, refreshing sensation |
| Shaving products | Cooling feel after shaving |
| Hair care | Invigorating, cooling scalp sensation |
| Body and bath | Refreshing coolness in washes and lotions |
In cosmetics, menthyl lactate gives a smoother, longer cooling than menthol and adds almost no odour, so it suits products that should feel refreshing without smelling strongly of mint. As a lipophilic ester it also blends well into oil-based and emulsion systems. Levels are kept low and confirmed by sensory and stability testing.
Market, Sourcing and Seasonality
- Menthol-linked supply – menthyl lactate is made from menthol, whose supply and price follow the mint harvest, so menthyl lactate pricing shows some seasonality too.
- Lactic acid feedstock – the other input is lactic acid, an established, largely bio-based commodity.
- Coolant trends – demand grows with the popularity of “cooling without mint odour” products in oral care, gum, skin care and beverages.
- Grade and documentation – buy against the purity, acid-value and melting-point specification with a per-batch COA.
For buyers, the practical points are to confirm the specification (especially acid value and odour), to plan around the menthol harvest cycle, and to treat menthyl lactate as one part of a coolant system rather than a standalone answer.
Frequently Asked Questions about Menthyl Lactate
What is menthyl lactate?
An ester of menthol and lactic acid (CAS 59259-38-0) used as a cooling agent – it cools without a strong mint odour.
What is the CAS number of menthyl lactate?
59259-38-0. A related stereoisomer, (-)-menthyl L-lactate, is CAS 185915-25-7.
How is it different from menthol?
Menthyl lactate is the ester of menthol with lactic acid: it gives a milder, longer-lasting cooling sensation with much weaker odour than menthol.
What does the acid value mean?
It measures residual free acidity (unreacted lactic acid); a low value (2.0 max here) indicates good neutralisation and purity.
Is menthyl lactate a coolant or a flavour?
Primarily a cooling agent (freshness agent) used in flavour, oral-care and cosmetic systems; it adds cooling with little odour.
How is it stored?
Sealed, cool and dry, away from heat and strong odours.
Related reading
- Menthyl lactate in oral care and personal care
- Menthyl lactate vs menthol and other coolants
- L-Menthol (CAS 2216-51-5): properties, production and applications
- L-Menthol vs peppermint oil and synthetic coolants
- Menthyl lactate (CAS 59259-38-0) – product page
PolyBlueChem supplies menthyl lactate (CAS 59259-38-0) to the specification above, with per-batch COA and SDS and FOB/CIF delivery. Contact us with your application, tonnage and delivery port.