Gromwell Root, (Natural Red), Lipophilic

Formulation Advice

When working with Gromwell Root Extract (INCI: Lithospermum erythrorhizon root extract, Coco-Caprylate/Caprate, Rosmarinus Officinalis (Rosemary) Leaf Extract, Tocopherols), formulators should be mindful of its powerful shikonin-type naphthoquinones, which impart the extract’s vivid purple-red hue and bioactive properties. These compounds offer unique value in skincare but are also sensitive to environmental stressors, making proper handling and formulation essential.

UV Stability

Shikonin derivatives are inherently UV-sensitive, with a tendency to undergo photo-oxidation and polymerization when exposed to light. This not only darkens the extract but also diminishes activity. Tocopherols and rosemary extract in this carrier provide built-in antioxidant protection, but for maximum stability, the finished product should be packaged in UV-protective containers and may benefit from additional antioxidants or UV-stable formulation partners.

Temperature Considerations

To preserve bioactivity, add the extract at the cool-down phase (<40–45°C) of emulsions. Exposure to higher processing temperatures accelerates degradation, color shifts, and potential precipitation. In anhydrous systems, avoid prolonged heating and ensure minimal oxygen exposure during mixing.

pH Range

This extract is pH-sensitive. The most stable range for both color and efficacy is pH 4.5–6.5. At higher pH values (above 7), shikonin derivatives rapidly shift in color (red to violet/brown) and undergo structural changes that compromise performance. For best results, formulate in mildly acidic, skin-friendly systems.

Formulation Contradictions

• Avoid alkaline products (bar soaps, high-pH cleansers) where the extract destabilizes.

• Limit pairing with pro-oxidant or peroxide-based ingredients that may accelerate oxidation.

• Exercise caution when combining with UV filters — while the extract naturally absorbs in the UVA range, compatibility testing is recommended to ensure filter stability.

• Not suited for high-heat processing or extended exposure to light/air during manufacturing.

Usage Recommendations

• Incorporate at cool-down stage of emulsions or directly into anhydrous formulas.

• Use protective packaging to shield from light, oxygen, and heat.

• Ideal for creams, serums, gels, emulsions, and oil-based treatments that showcase both activity and the extract’s striking natural pigment.

• Tocopherols and rosemary extract already provide synergistic antioxidant support, but additional stabilizers may be added for long-term storage.