Dimethyl Isosorbide (DMI): Complete Cosmetic Formulation Guide
Dimethyl Isosorbide (DMI) is a versatile cosmetic formulation solvent used to help dissolve, pre-disperse and evenly incorporate selected cosmetic ingredients into serums, gels, creams, lotions and anhydrous systems. This JustGlow guide explains how to use DMI in cosmetic formulations, how much DMI to use, how to build a DMI premix, and how to test clarity, crystallisation, compatibility and stability.
Important: DMI is a concentrated cosmetic raw ingredient, not a finished skincare product. It must be accurately weighed and incorporated into a properly developed cosmetic formulation. Do not apply DMI directly to skin, use it undiluted, ingest it or add it to a purchased finished product.
Shop JustGlow Dimethyl Isosorbide (DMI) for current pack sizes, batch information and technical documents.
In this formulation guide: what DMI is; what it does; recommended use levels; solubility and phase selection; hot- and cold-process incorporation; DMI in oil serums, water-based serums and emulsions; worked starting frameworks; troubleshooting; compatibility; FAQs; storage and professional compliance.
Dimethyl Isosorbide (DMI) at a glance
| Property | JustGlow formulation guidance |
|---|---|
| INCI name | Dimethyl Isosorbide |
| CAS number | 5306-85-4 |
| Appearance | Clear, colourless liquid |
| Ingredient category | Functional cosmetic ingredient; solvent and formulation carrier |
| Typical use level | 1–10% of the finished formulation |
| Practical starting point | 3–5% when only modest solvent support is needed; increase gradually only when justified by solubility testing |
| JustGlow maximum guidance | Do not exceed 10% of the finished formulation unless your own qualified assessment supports a different level |
| Phase | Water phase, cool-down phase or a separate active premix, depending on the formula and the ingredient being dissolved |
| Process | Suitable for cold processing; gentle heat may be used when required by the active or the selected solvent system |
| pH | Generally compatible with typical cosmetic pH ranges, but the finished formula must be tested after all ingredients are added |
| Preservation | DMI is not a preservative and does not replace a suitable preservation system in water-containing products |
What is Dimethyl Isosorbide and what is it used for?
Dimethyl Isosorbide, usually shortened to DMI, is a clear liquid solvent used in cosmetic formulation to help manage ingredients that are difficult to dissolve or distribute evenly. It is particularly useful when a formulator needs to prepare a concentrated side phase before adding an ingredient to a water-based formula, emulsion or selected anhydrous system.
DMI is made from isosorbide, which is commonly produced from glucose or starch-based plant feedstocks. This means it may be described as nature-derived or naturally sourced, depending on the manufacturer's supply chain and documentation. It is not a raw plant extract or a natural oil: it is a refined, defined cosmetic raw material. Always use the INCI name and the batch-specific technical documents for the material you are actually formulating with.
In JustGlow product information, DMI is positioned as a cosmetic solvent, carrier and formulation aid. It can support solubilisation, uniform mixing and formula consistency. It is not marketed by JustGlow as a treatment, medicine, preservative or guarantee of improved skin performance.
What does DMI do in a cosmetic formula?
- Helps dissolve selected ingredients: DMI can be useful for preparing a liquid concentrate of certain powders or crystalline materials before they are added to the main batch.
- Supports even distribution: a properly prepared premix can reduce dry pockets, visible particles and uneven concentration in the finished product.
- Helps manage formula clarity: in suitable systems, DMI can help maintain a more uniform appearance; clarity must still be checked after dilution and cooling.
- Works across different product formats: it may be used in water-based serums, gels, emulsions and selected anhydrous products, provided the complete system is compatible.
- Gives the formulator more control: DMI allows you to test a defined solvent-to-active ratio rather than adding a difficult powder directly to the main batch.
DMI does not dissolve every cosmetic ingredient. Solubility depends on the active, concentration, temperature, water content, pH, electrolytes, polymers, oils, waxes and order of addition. A solution that is clear while warm may become cloudy or form crystals during cooling, dilution or storage.
How much DMI should you use?
| DMI level in the finished formula | Useful development context |
|---|---|
| 1–2% | A low starting level when only light solvent or carrier support is required. Confirm that it is sufficient for the selected ingredient. |
| 3–5% | A practical screening range for many serum, gel and emulsion prototypes. Test skin feel, clarity, viscosity and active stability. |
| 5–10% | A higher solvent level for a more demanding solubility problem or a concentrated premix. Check sensory profile, packaging, preservation and finished-product safety carefully. |
| Above 10% | Outside JustGlow's standard guidance. Do not increase the level simply because an ingredient is not dissolving; redesign the solvent system or obtain qualified technical advice. |
The percentage of DMI is calculated against the total finished batch. For a 100 g batch, 5% DMI means 5.00 g DMI. The active and DMI used in a premix must both be included in the formula total; the solvent is not “free” or added on top of 100%.
DMI solubility and phase selection
DMI is a polar, water-compatible solvent, but “water-compatible” does not mean that it will behave identically in every oil or emulsion. Before making a full batch, prepare a small compatibility trial using the actual active, the actual DMI level and the intended formula base.
| Formula type | How DMI may be used | What to check |
|---|---|---|
| Water-based serum or gel | Add DMI to the water or solvent phase, or use it in a separate active premix before dilution. | Clarity, precipitation, viscosity loss, pH and preservative compatibility. |
| Oil-in-water emulsion | Use in a compatible aqueous/cool-down premix or add a validated premix after emulsification. | Emulsion stability, viscosity, droplet structure, separation and active crystallisation. |
| Water-in-oil emulsion | Use only where the selected internal or external phase can accommodate DMI without disrupting the emulsifier system. | Phase balance, viscosity, separation and compatibility with the chosen emulsifier. |
| Anhydrous oil serum | Use only after confirming that DMI remains uniform in the selected emollient blend. A polar solvent and low-polarity oil may require a tailored solvent system. | Haze, separation, settling, crystals, odour and low-temperature stability. |
| Balms and sticks | Test DMI before adding waxes or high-viscosity structuring materials. The final solvent level may change hardness and pay-off. | Hardness, sweating, graininess, syneresis, crystal growth and package compatibility. |
How to incorporate DMI into a cosmetic formulation
- Define the problem. Identify which ingredient is not dissolving or distributing evenly and confirm its recommended solvent, use level and processing conditions.
- Calculate the finished percentage. Decide the DMI level against the total batch. For a 100 g formula, 3% is 3.00 g and 10% is 10.00 g.
- Prepare a side phase. Weigh DMI into a clean, dry vessel. Add the selected active gradually while mixing. Do not pour a large amount of powder into the main batch and hope that DMI will correct it afterwards.
- Mix at room temperature first. Allow the active to wet out and assess whether it dissolves without heat. This protects heat-sensitive materials and makes the trial easier to interpret.
- Use gentle heat only when appropriate. If the supplier's documentation permits heating, warm the premix gradually and mix until uniform. Avoid unnecessary high temperatures and protect volatile materials from evaporation.
- Inspect the concentrate. Look for particles, haze, sediment, colour change and undissolved material. Do not call a mixture dissolved merely because the powder is temporarily hidden.
- Add to the correct phase. Introduce the uniform premix into the water phase, oil phase or cool-down phase selected for the formula. Follow the emulsifier and active supplier's order-of-addition guidance.
- Mix until homogeneous. Use sufficient agitation to distribute the premix without excessive air incorporation.
- Check the finished formula. Measure appearance, odour, pH, viscosity and, where relevant, density. Recheck after 24–48 hours and during stability testing.
- Record the result. Keep the active-to-DMI ratio, temperature, mixing time, batch size, appearance and stability observations so the process can be repeated.
Using DMI in water-based serums and gels
For a water-based product, DMI can be added to the aqueous phase or used to prepare a separate active concentrate. The best location depends on whether the active is water-soluble, partially soluble or requires a mixed solvent system.
When preparing a DMI premix, dissolve the selected active in DMI first and then add the concentrate slowly to the water phase with mixing. Avoid adding a concentrated solvent premix too quickly to a polymer-thickened gel because local solvent concentration can reduce viscosity or create stringy, uneven hydration.
- Use purified or deionised water where the formula requires it.
- Add DMI before or after polymer hydration only when supported by the thickener's compatibility data.
- Check whether electrolytes, salts or a pH adjustment change the solubility of the active.
- Do not assume that a clear concentrate will remain clear after dilution into a high-water formula.
- Choose and validate a broad-spectrum preservative for the complete water-containing formula.
Using DMI in creams and lotions
In an oil-in-water emulsion, DMI may be used as part of a water-phase premix, a cool-down addition or, where compatible, a separate active phase. The correct choice depends on the active's solubility and the emulsifier system. Add the premix slowly and mix until fully uniform.
Do not assume that adding DMI after emulsification is always better. Post-emulsion addition can change viscosity, sensory properties and emulsion stability. Compare a water-phase addition, a cool-down addition and an oil-compatible alternative in small trials before selecting the manufacturing process.
For every emulsion trial, assess:
- Immediate appearance and texture;
- pH after equilibration;
- Viscosity and spreadability;
- Centrifuge or short-term separation behaviour;
- Low- and elevated-temperature stability;
- Crystallisation or precipitation of the active;
- Preservative performance and microbiological quality;
- Compatibility with the bottle, pump, gasket, liner and label adhesive.
Using DMI in oil serums and anhydrous formulas
DMI is not an oil in the same way as squalane, triglycerides or plant oils. In an anhydrous formula, it must be tested with the complete emollient blend. A DMI-containing oil serum can be visually clear while warm and then become hazy or separate as it cools, so cooling and storage observations are essential.
A useful development approach is to make three small trials: a low-DMI version, a mid-range version and a higher-DMI version within the 1–10% guidance. Compare clarity, feel, separation and active stability rather than assuming that the highest solvent level is best.
Worked development framework: DMI and THDC oil serum
The following is a starting framework for a formulator testing an anhydrous antioxidant serum. It is not a finished commercial formula and does not replace safety assessment or stability testing.
| Ingredient | Starting level | Formulation role |
|---|---|---|
| Dimethyl Isosorbide (DMI) | 5–10% | Solvent and carrier; test whether it remains uniform in the chosen oil blend |
| Tetrahexyldecyl Ascorbate (THDC) | 10–15% | Oil-soluble vitamin C derivative |
| Tocopherol | 0.2–1% | Oil-phase antioxidant support |
| Compatible emollients such as squalane | To 100% | Vehicle, dilution and sensory profile |
Suggested screening method: weigh DMI and THDC together, mix until uniform, add tocopherol, then add the remaining emollients gradually. Observe the concentrate and finished serum at room temperature, after cooling, at low temperature and after storage. If the product separates or becomes cloudy, change the solvent-to-oil balance or select a more compatible carrier system rather than increasing DMI automatically.
View JustGlow THDC oil-soluble vitamin C for the ingredient page and current availability.
Worked development framework: DMI active premix for a water-based serum
This framework shows how a formulator can test DMI as part of an active premix. It is deliberately not a universal recipe because the correct DMI percentage depends on the chosen active and its supplier data.
| Ingredient group | Starting approach | Important check |
|---|---|---|
| Purified water | Quantity sufficient to 100% | Water quality and microbiological control |
| Humectant or water-compatible co-solvent | Use the level suitable for the intended skin feel | Sticky feel, viscosity and preservative compatibility |
| DMI | Start at 3–5%; increase only after solubility testing | Clarity, active precipitation and polymer compatibility |
| Selected cosmetic active | Use the supplier's recommended level | True dissolution after dilution, cooling and pH adjustment |
| Thickener | Use the supplier's recommended process | Viscosity loss, clumping and addition order |
| Preservative | Use the selected preservative supplier's recommended level | Finished-product preservation and challenge testing where applicable |
| pH adjuster | Quantity sufficient for the target pH | Active stability, preservative range and skin compatibility |
DMI with difficult-to-dissolve cosmetic ingredients
DMI can be useful when an active is difficult to dissolve, but every active requires its own screening trial. Start with a small amount of the actual raw material and record the minimum DMI level that creates a stable, uniform concentrate.
- Powdered actives: wet the powder gradually and mix thoroughly before adding water or the main phase.
- Oil-soluble actives: confirm that the DMI-containing concentrate is compatible with the selected emollients and does not create haze or separation.
- Partially water-soluble actives: test the concentrate after dilution because precipitation may appear only after water is added.
- Acidic or alkaline materials: assess the pH of the final formula, not only the pH of the DMI premix.
- Polymer-thickened systems: test solvent addition before and after thickening because DMI can affect hydration and viscosity.
Never rely on a list of “compatible actives” without testing the exact supplier grade, concentration and finished-product base. Compatibility is a property of the complete formula, not just a pair of ingredients considered in isolation.
Common DMI formulation problems and solutions
The active is still not dissolving
Check the active's recommended solvent, particle size, concentration and temperature. Confirm that the DMI amount is calculated against the finished batch. Try a smaller active concentration or a blend of compatible solvents. Do not keep increasing DMI above the recommended range without a qualified assessment.
The concentrate is clear but the finished product is cloudy
The active may have exceeded its solubility after dilution. The water content, pH, electrolytes or temperature may have changed the solvent balance. Test the active at the same final concentration in the same base before making a full batch.
Crystals appear after cooling
Warmth can temporarily hold more material in solution. Allow the product to cool fully, then inspect it again after 24–48 hours and during stability testing. Reduce the active concentration, adjust the solvent system or choose another product format if crystals persist.
The emulsion becomes thin or separates
DMI may be interacting with the polymer, emulsifier or phase balance. Compare different addition points, reduce the solvent level, review the emulsifier's tolerance and repeat the test with the active premix rather than DMI alone.
The product feels sticky or wet
Review the total polar-solvent level, humectants and water content. A lower DMI level or a different co-solvent may give a better sensory profile. Sensory acceptability must be assessed in the finished product, not predicted from the raw material alone.
The formula changes colour or odour
Check the active, water quality, heat exposure, air, light, trace metals, packaging and contamination. Compare the DMI trial with a control formula and retain samples for investigation.
What DMI is not
- DMI is not a preservative and does not protect a water-based product from microbial growth.
- DMI is not an emulsifier and cannot replace a properly selected emulsifier or stabilising system.
- DMI is not a finished skincare product and should not be applied directly or used undiluted.
- DMI is not a guarantee of active performance. A solvent can improve handling or solubility without proving a benefit in the finished product.
- DMI is not a substitute for formulation testing. The finished product still needs stability, packaging, microbiological and safety assessment appropriate to its intended use.
DMI versus DOI: do not confuse these ingredients
Dimethyl Isosorbide (DMI) and Isosorbide Dicaprylate (DOI) are different cosmetic ingredients. DMI is a low-viscosity, polar solvent and formulation carrier. DOI is an oil-compatible emollient and texture ingredient. Their INCI names, sensory profiles, solubility behaviour and formulation roles are not interchangeable.
Choose DMI when your primary problem is solvent support or active premixing. Choose DOI when you are developing an anhydrous emollient system and want an oil-phase texture modifier or emollient. Always formulate from the actual INCI, specification and technical documentation.
Frequently asked questions about Dimethyl Isosorbide
What is DMI in skincare formulation?
DMI is Dimethyl Isosorbide, a cosmetic solvent and formulation carrier. It is used by formulators to help dissolve or distribute selected ingredients in serums, gels, creams, lotions and some anhydrous systems.
What is the recommended DMI percentage?
JustGlow guidance is 1–10% of the finished formulation. A practical development trial often starts at 3–5%, then adjusts only after testing the active, base, appearance, stability and sensory profile.
Can DMI be used in a water-based serum?
Yes, where the complete formula is compatible. DMI may be added to the water phase or used in a separate active premix. Check clarity, precipitation, viscosity, pH and preservation after dilution.
Can DMI be used in an oil serum?
It can be tested in selected anhydrous systems, but DMI is not an ordinary oil. Confirm that it remains uniform with the chosen emollients and does not cause haze, separation or crystallisation during cooling and storage.
Can I add DMI directly to the skin?
No. JustGlow DMI is supplied as a cosmetic ingredient for formulation use only. Do not apply it undiluted, ingest it or use it as a finished cosmetic.
Can DMI replace a preservative?
No. DMI does not replace a broad-spectrum preservative. Any water-containing product needs a suitable preservation strategy and finished-product microbiological assessment.
Can DMI replace an emulsifier?
No. DMI may affect an emulsion's phase balance, but it does not create or stabilise an emulsion by itself. Use a suitable emulsifier and follow the emulsifier supplier's process.
Can I heat DMI?
DMI may be used in hot or cold processing, but heat should be used only when needed and within the limits of the selected active, packaging and manufacturing process. A cool-down premix is often preferable for heat-sensitive ingredients.
Is DMI natural?
DMI may be described as nature-derived when it is manufactured from plant-based glucose or starch feedstocks. It is a refined cosmetic raw material, not a plant extract or natural oil. Confirm the appropriate description from the current supplier documentation.
Is DMI the same as Dimethyl Isosorbide used in medicine?
The INCI name is Dimethyl Isosorbide, but JustGlow supplies this material as a cosmetic raw ingredient. It is not supplied as a medicine and must not be used to make medical or therapeutic claims.
How do I know whether DMI has worked?
Check the complete formula rather than the premix alone. Record appearance, clarity, pH, viscosity, odour, separation, crystals and active assay where appropriate immediately after manufacture and during stability testing.
Storage, handling and technical documents
Keep the DMI container tightly closed and protected from contamination, light and moisture. Follow the batch label and current JustGlow Safety Data Sheet and Certificate of Analysis for the applicable storage and shelf-life information. Use clean, dry equipment and avoid introducing water or other raw materials into the container.
View DMI batch information, COA and technical documents.
Professional formulation and UK compliance note
JustGlow DMI is supplied as a cosmetic raw ingredient for professional formulation use only. The formulator or finished-product manufacturer remains responsible for confirming ingredient suitability, determining the correct concentration, conducting stability and microbiological assessment, checking packaging compatibility, substantiating cosmetic claims and meeting the legal requirements of the intended market.
For a finished cosmetic placed on the Great Britain market, the responsible business must ensure that the product is appropriately safety assessed, supported by the required product information and manufactured in accordance with applicable good manufacturing practice and notification requirements. This guide is formulation education, not a performance warranty or a substitute for a Cosmetic Product Safety Report.
Cosmetic ingredient for formulation use only. Do not apply undiluted.