Yes, jojoba oil can effectively function as a serum. Its composition closely resembles the skin's natural sebum, allowing for easy absorption and providing hydration and a protective barrier. It's particularly beneficial for balancing oil production and calming irritated skin.

Dermatologists often recommend jojoba oil due to its moisturizing and anti-inflammatory properties. It's generally considered safe for most skin types, including sensitive and acne-prone skin, as it's non-comedogenic and unlikely to clog pores.

Jojoba oil is generally well-tolerated, but a potential disadvantage is allergic reaction, although rare. Perform a patch test before applying it liberally, especially if you have sensitive skin or known allergies to plant-based oils.

Determining the 'no. 1' face serum is subjective and depends on individual skin needs and concerns. Popular and highly-rated serums often contain ingredients like hyaluronic acid for hydration, vitamin C for brightening, or retinol for anti-aging, so consider your specific goals.