Microblading (manual) can last anywhere from 6 months to 1 year, usually. Microneedling (machine) can last anywhere from 1 to 5 years, typically, before needing a touch up.
Cosmetic grade pigments are usually made with an iron oxide base, as opposed to the carbon-based body tattoo pigments. Iron oxide-based pigments are not as stable in body long-term, nor fade-resistant to UV sunlight as the carbon-based pigments.
Sunlight is tattoo’s worse enemy! So, a person’s lifestyle, environment, and amount of direct sunlight exposure both with and without sunscreen will greatly determine how soon a touch up is needed.