pH and compatibility for a 2% BHA acne gel using Acacia Salicylic Acid

Asked by: Anonymous On: June 05, 2026 Product Type: Cosmetics Answered

Question

Please help check the ingredient formula for this formula.

Ingredient %
water 79
2Na edta 0.1
vitamin b3 5
vitamin b5 1
Natural Betaine 1
zinc pca 0.7
Sodium PCA 1
butylene 3
glycerin 1
xanthan gum 0.4
Acacia Salicylic Acid 4
D-Mannose Skin Prebiotic 1.5
WaterLube Slip 1.5
Microcare PHC 0.8

If I want to use Acacia Salicylic Acid 4 to get BHA 2% for use in caring for/treating comedonal acne, what pH should this be to be suitable?

And can the other ingredients work together with Acacia Salicylic Acid?

If I also want to reduce inflamed acne, swelling, and redness, could you recommend extracts and percentages that can be compatible with the ingredients above?

Answer

Your formula totals 100.0% and is broadly compatible as a water-gel acne serum/gel. With Acacia Salicylic Acid 4%, the salicylic acid content is approximately 1.8–2.0% BHA depending on assay, and this is already at the catalog maximum usage level for this ingredient.

Recommended final pH

  • Target: pH 4.2–4.5
  • Acceptable working range: pH 4.0–5.0
  • Do not set below pH 4.0 because Acacia Salicylic Acid, Microcare PHC equivalent, Zinc PCA, D-Mannose, and several actives are specified from about pH 4 upward. Too low pH can also increase irritation.
  • Do not raise too high if the goal is comedolytic BHA performance; pH around 4.2–4.5 gives a better balance between BHA effect and tolerability.

Compatibility review

  • Acacia Salicylic Acid 4%: suitable for leave-on acne/exfoliating formula; use at max level, so irritation/stability testing is important.
  • Niacinamide 5%: acceptable in this pH range; avoid pH below 4 and avoid long heating.
  • Zinc PCA 0.7%: compatible; best kept around pH 4–6 to reduce precipitation risk.
  • Panthenol 1%, Sodium PCA 1%, D-Mannose 1.5%, WaterLube™ Slip 1.5%, Microcare PHC eq. 0.8%: compatible with the recommended pH range.
  • Natural Betaine 1%: compatible, but for reducing BHA irritation the catalog usage for Natural Betaine is typically higher; consider 2–3% if the texture is not too sticky, subtracting from water.
  • Xanthan Gum 0.4%: workable, but may feel stringy/sticky with the high humectant load. If the gel feels too heavy, test lowering to 0.2–0.3%.
  • Microcare PHC eq. 0.8%: within usage range and pH range; for commercial production, preservative challenge testing is still required.

Suggested anti-redness / inflamed-acne additions
Add only a small set at a time and reduce water accordingly.

Option Ingredient Suggested % Notes
Gentle redness/irritation support Licorice Extract (Licochalcone A 1%, Water-Soluble) 0.5–1.0% Water-soluble, suitable for redness, inflammation, oiliness/acne; pH 3.5–6.5.
Barrier + post-acne redness support Centella Asiatica Extract (Madecassoside 90%) 0.3–1.0% Add in cool-down/final step; pH 4–6.5; avoid heat.
Soothing irritation from BHA Allantoin 0.2–0.5% Keep ≤0.5% for room-temperature solubility; can be dissolved in the water phase.
Stronger inflamed-acne support QD-365 Anti-Acne Complex 0.5–1.5% Water-soluble, anti-acne/anti-inflammatory. Because it also contains a salicylic derivative, use low level first with Acacia Salicylic Acid 4% to avoid over-exfoliation.
Concentrated licorice alternative Hi-LiconeA™ Licorice Extract (Licochalcone A 20%) 0.1–0.2% Dissolve in glycol first; not directly water-soluble. Use this instead of the water-soluble licorice option, not both initially.

Practical recommendation
For this formula, the simplest balanced version is: keep Acacia Salicylic Acid 4%, set final pH 4.2–4.5, and add Licorice Extract (Licochalcone A 1%, Water-Soluble) 0.5–1% + Centella Asiatica Extract (Madecassoside 90%) 0.5–1%. If irritation is a concern, add Allantoin 0.2–0.3% and/or increase Natural Betaine to 2%. Reduce water by the same total percentage added.

Tags

Gel Acne Treatment pH Compatibility Ingredient Interaction Redness Reduction Skin Inflammation