^"
You should never give blood if:
You have ever had syphilis, HTLV (Human T - lymphotropic virus), HIV or hepatitis C.
You've ever worked as a prostitute.
You've ever injected yourself with drugs - even once.
You should not give blood for 12 months after sex with:
A man (if you?re a male). Men who have had anal or oral sex with another man (with or without a condom) are deferred from blood donation for 12 months. For more information click here.
A man who has had sex with another man (if you're a female).
A prostitute.
Anyone who has ever injected themselves with drugs.
Anyone with haemophilia or a related blood clotting disorder who has received clotting factor concentrates."^
Why is it if someone has ever worked as a prostitute they can't donate? Yet a man who has sex with one only has to wait 12 months? 
And at what point does being paid for sex alter your blood? Surely that should say anyone who has regular unprotected sex with randoms.
I'm not sure if I can donate, I'm on some medication but would love to. :(