Essential oil lemon 10ml lemon essential oil can be diluted and applied topically to your skin, as well as diffused into the air and inhaled. some people swear by lemon essential oil as an ingredient that fights exhaustion, helps with depression, clears your skin, kills harmful viruses and bacteria, and reduces inflammation. it typically takes around 45 lemons to fill one 15ml essential oil bottle, making each drop have a strong, powerful aroma.