•
before donating blood you are usually tested to make sure you don't have any of the infections that can be transmitted through blood like HIV and hepatitis B and C. But since there is a window period, which is the time from getting the infection till it shows in the blood, it is better not to donate blood during this period which is usually around 6 months. So better not to donate blood for 6 months after you had the tattoo.
•
