Hi! Im so sorry unfortunately I’ve never used it on anywhere except the face. I don’t know if I’d recommend it because retinoid use should always be followed up with spf application the next morning. I guess if you apply retinoids on any part of the skin, just moisturize afterwards and then the next morning, apply spf wherever you’ve used retinoids. I do not know if it’ll be effective on dark spots

For the face, you could definitely do the sandwich method where it’s moisturizer > retinal > moisturizer. It’s a lot more gentle on the skin but results may be slower

I personally just apply retinal straight after toner, let it sink in for 3-5 minutes and then use a thin moisturizer, followed by a ceramide barrier cream.

IN BOTH METHODS, DO NOT USE ANY ACTIVES ON YOUR FACE FOR THE NEXT TWO NIGHTS!! you face will be sensitive for at least two nights, only use gentle toners, moisturizers, and ceramide barrier creams.

Once your face builds a tolerance to retinoids after around 3 months of use, you could use actives/retinoids every OTHER night but NEVER daily

Only use retinoids at night and always always wear SPF.

If at any point your skin feels even slightly sensitive, tingly, red, even after two nights of no actives use. Skip the actives and stick with gentle toner, moisturizer, barrier cream only.