Lavender oil is included for its conditioning properties. Its role is to help make the nail plate feel less dry and contribute to a smoother, neater surface finish after the polish dries. This can be particularly helpful if your nails feel brittle or look uneven.
Essential oils like lavender are generally well-tolerated in cosmetic formulations, but as with any ingredient, individual sensitivity is possible. To check, apply a small amount of polish to a single nail and observe for 24 hours. If you have known allergies to lavender or other essential oils, or if you experience redness, itching, or swelling on the skin around the nail, discontinue use. Avoid applying the polish to any broken or irritated skin around the nail cuticle.