If you have a tattoo, you can only donate blood if you meet certain requirements. A good rule of thumb is that you may not be able to give blood if your tattoo is less than a year old. This goes for piercings and all other non-medical injections on your body, too.
Why, is because introducing ink, metal, or any other foreign material into your body affects your immune system and may expose you to harmful viruses. This can affect what’s in your bloodstream, especially if you got your tattoo somewhere that isn’t regulated or doesn’t follow safe practices.
answered on 5 Jun 2019:
last edited 5 Jun 2019 5:25 am
I think it is because when you donate blood, you want to minimise how much exposure to pathogens the blood has encountered. So, if one recently got a tattoo, then you recently introduced potential pathogens and so then it becomes a risk to the blood donation organization.
However, there are time limits after getting tattoos/piercings etc where it is safe to donate blood! For those restrictions, you’d speak with whoever is collecting the blood/the hospital attendant