Can I use this oil directly on my skin to target oily areas on my face?

No, you should never apply this undiluted essential oil directly to your skin. It is highly concentrated and can cause irritation, redness, or sensitisation. For facial use, especially on skin that tends to look shiny, it must be diluted to a very low concentration in a suitable base. A common safe dilution for facial products is 0.5–1%, which is about 1 drop of essential oil per 2 teaspoons (about 10 ml) of a non-comedogenic carrier oil like jojoba or hazelnut, or an unscented moisturiser.

Grapefruit oil is often chosen for formulas designed for oily-looking skin due to its astringent properties, but it must be part of a properly formulated blend. Crucially, this oil is known to increase the skin's sensitivity to sunlight (a phototoxic effect). Therefore, any facial blend containing it should only be used in the evening, and you should avoid sun exposure on the treated areas for at least 12 hours. As with any new skincare ingredient, a patch test on a small area is recommended. This product is for external cosmetic use only and is not intended to treat acne or other skin conditions.