Ingredient sourcing note: Some ingredients mentioned in this article are available from The Skin Science Company (theskinsciencecompany.com.au), an Australian cosmetic raw materials supplier. We recommend them based on the quality and availability of their products. We have no commercial, affiliate, or sponsorship relationship with them and receive no payment or commission for these mentions.
Finding a solution for both stubborn breakouts and facial redness can feel like a never-ending cycle, but a DIY azelaic acid serum might be the missing piece in your skincare routine. Azelaic acid is a naturally occurring dicarboxylic acid that has gained immense popularity for its ability to soothe the appearance of rosacea-prone skin while simultaneously clearing the look of acne and evening out skin tone. For intermediate and advanced DIY formulators, working with azelaic acid presents a unique but rewarding challenge due to its tricky solubility profile. In this guide, we will break down how to formulate a stable, effective serum that delivers professional-quality results from the comfort of your own home lab.
Why Formulate a DIY Azelaic Acid Serum?
Azelaic acid is often hailed as a “multitasking” ingredient because it addresses multiple skin concerns without the harshness associated with some other acids. Unlike Alpha Hydroxy Acids (AHAs) or Beta Hydroxy Acids (BHAs), azelaic acid is generally better tolerated by those with sensitive or reactive skin types. When you create your own DIY azelaic acid serum, you have the advantage of controlling the concentration, ensuring the pH is optimal for your skin, and excluding unnecessary fillers or fragrances that might trigger irritation.
The primary benefits of incorporating azelaic acid into your formulations include its ability to visibly reduce redness associated with rosacea and its gentle exfoliating properties that help keep pores clear. Furthermore, it acts as a tyrosinase inhibitor, which means it can help fade the appearance of post-inflammatory hyperpigmentation (PIH) left behind by old blemishes. By mastering this formulation, you can provide your skin with a high-performance active that is both calming and clarifying.
The Science of Azelaic Acid Solubility and pH
The most significant hurdle when making a DIY azelaic acid serum is its poor solubility in both water and oil. Many beginners find that their azelaic acid simply sits at the bottom of the beaker or creates a “gritty” texture in the final product. To achieve a smooth, professional serum, you must use a high percentage of a solvent like propanediol or ethoxydiglycol. Research suggests that while azelaic acid is difficult to dissolve, using a 1:2 or 1:3 ratio of azelaic acid to propanediol, combined with gentle heating, can create a stable solution [1].
Maintaining the correct pH is equally vital for both the stability of the molecule and the comfort of your skin. Azelaic acid is most stable and effective in a pH range of 4.0 to 5.5 [2]. If the pH is too high, the acid may become ionized and less effective at penetrating the skin’s lipid barrier; if it is too low, it may cause unnecessary stinging or irritation. We recommend aiming for a final pH of approximately 4.8 to 5.2 for the best balance of efficacy and skin tolerance.
| Property | Optimal Range / Requirement |
|---|---|
| Recommended Usage Rate | 5% to 10% (up to 20% for advanced formulas) |
| Optimal pH | 4.0 – 5.5 |
| Best Solvents | Propanediol, Ethoxydiglycol, Propylene Glycol |
| Solubility Type | Sparingly soluble in water; requires glycol-based solvents |
| Compatibility | Niacinamide, Panthenol, Hyaluronic Acid, Allantoin |
A Pro-Level DIY Azelaic Acid Serum Formula
This formula is designed for a 10% concentration, which is an excellent “sweet spot” for most skin types. It utilizes a high percentage of propanediol to ensure the azelaic acid stays in solution, along with soothing agents like Panthenol and Allantoin to support the skin barrier. Please ensure you are working in a clean environment with sanitized equipment before you begin.
| Phase | Ingredient | Weight (%) | Function |
|---|---|---|---|
| A | Distilled Water | 57.50 | Solvent / Base |
| A | Glycerin | 3.00 | Humectant |
| A | Panthenol (Pro-Vitamin B5) | 1.00 | Soothing / Hydrating |
| A | Allantoin | 0.50 | Anti-irritant |
| B | Propanediol | 25.00 | Solvent / Penetration Enhancer |
| B | Azelaic Acid | 10.00 | Active Ingredient |
| C | Xanthan Gum (Soft/Clear) | 0.50 | Thickener / Stabilizer |
| C | Liquid Germall Plus | 0.50 | Broad-Spectrum Preservative |
| C | Citric Acid (10% solution) | Q.S. | pH Adjuster |
| Total | — | 100.00 | — |
Step-by-Step Instructions
- Prepare Phase A: In a sanitized heat-proof beaker, combine the distilled water, glycerin, panthenol, and allantoin. Stir until fully dissolved.
- Prepare Phase B: In a separate heat-proof beaker, combine the propanediol and azelaic acid. Place this beaker in a water bath (double boiler) and heat gently to approximately 60-70°C, stirring constantly until the azelaic acid is completely dissolved and the liquid is clear.
- Combine: Slowly add the heated Phase B into Phase A while stirring. You may notice a slight temporary cloudiness as the temperatures equalize, but it should clear with stirring.
- Thicken: Sprinkle the xanthan gum over the mixture and use a high-shear mixer (like a stick blender or lab overhead stirrer) for a few seconds to hydrate the gum. Alternatively, create a slurry with a small amount of glycerin before adding to the main batch to avoid “fish eyes.”
- Cool and Preserve: Once the serum has cooled to below 40°C, add your preservative (Liquid Germall Plus).
- pH Check: Use a calibrated pH meter to check the pH. If it is above 5.5, add a drop or two of citric acid solution. If it is below 4.0, you may need a tiny amount of L-Arginine or Triethanolamine to raise it. Aim for a final pH of 5.0.
Practical Tips for Success
Formulating with azelaic acid requires patience. If you find that your DIY azelaic acid serum begins to crystallize after a few days, it usually indicates that there was not enough solvent (propanediol) or that the temperature was not maintained long enough during the dissolution phase. Always ensure your azelaic acid is a fine powder; if it has clumps, sift it before adding it to the propanediol to ensure even heating and dissolution.
For those dealing with active acne, you might consider adding 2% Niacinamide to Phase A. Niacinamide works synergistically with azelaic acid to further reduce the appearance of redness and regulate the look of oily skin. However, be mindful that Niacinamide can raise the pH of your formula, so a final pH check is non-negotiable when adding extra actives.
Usage and Storage
Because this serum contains a significant amount of active acid, we recommend introducing it slowly into your routine. Start by applying it every second night after cleansing and before moisturizing. If no irritation occurs, you can increase usage to once daily. Always wear a broad-spectrum sunscreen during the day, as any exfoliating acid can increase the skin’s sensitivity to the sun.
Store your finished serum in a cool, dark place, preferably in an airless pump or a dark amber glass dropper bottle. While the preservative will keep it safe from microbial growth, protecting the active ingredients from light and air will ensure the serum remains potent for its entire shelf life, which is typically 3 to 6 months for home-formulated products.
Conclusion
Creating your own DIY azelaic acid serum is a fantastic way to target rosacea and acne with a customized, high-performance product. While the solubility of azelaic acid can be a bit of a “fair dinkum” challenge for formulators, following the correct heating and solvent protocols will result in a silky, effective serum that rivals expensive store-bought versions. Remember to always prioritize pH testing and sanitation to ensure your creations are safe and stable. If you’re ready to start formulating, you can find all the high-quality ingredients you need, including cosmetic-grade azelaic acid and propanediol, at The Skin Science Company, your trusted Australian supplier for professional skincare raw materials.
References
- Chemist’s Corner: Dissolving Azelaic Acid in Cosmetic Formulations
- Szeasychem: Formulating with Azelaic Acid Stability Tips
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