Lemon Juice Worst Irritant No known benefits Lemon Juice at a glance Juice from the citrus lemon, AKA Citrus limon and Citrus medica limonum Its high acidity can cause barrier disruption Contains antioxidants and photosensitive compounds Better to consume orally than apply topically Lemon Juice description The juice from the citrus fruit lemon, often touted in the world of skin care as being a natural option for brightening skin. The truth is that lemon juice is highly acidic, with a very low pH that’s exceedingly sensitising to skin. Lemon juice has a pH of 2, and comparing an ingredient with that pH to just one number up (that being pH 3) is like the difference between a minor tremor in the ground and a catastrophic earthquake. Lemon juice applied to skin can cause photosensitivity, which is due to a volatile fragrance chemical known as limonene, which is abundant in lemon juice. Bottom line: There’s no research showing that lemon juice has a positive effect on brightening an uneven skin tone, yet it’s clear this ingredient is a potent skin sensitizer. Given its antioxidant content, lemon juice has its benefits, but far better to consume it orally than apply it topically. Related ingredients: Citrus Medica Limonum Lemon Lemon Oil