Japani Oil is for external use only on the penis and may support sexual performance, although scientific evidence is limited. Before sexual activity, take a few drops of the oil and gently massage it onto the penis, avoiding the tip, and allow it to absorb for several minutes. Stop use immediately if any irritation, burning, or itching occurs, and test a small amount on your forearm before first use to check for sensitivity. Its effects can vary between individuals, so it should be used appropriately according to individual suitability and condition.