My understanding is that tattoos are only a problem with MRIs if your tattoo was done twenty-some years ago. Tattoo ink used to contain some metallic powder, but that hasn't been the case for 20+ years now. The industry is much more regulated than it used to be.
I had both permanent eye-liner and fulll lips done about 6 years ago. The eye-liner is a dark brown and still looks great. I have very dark lashes, so the liner merely makes my lashes look fuller at the base. I'm not worried that it will look unnatural as I age because it seems to be fading gradually. By the time I'm in my sixties, it will probably be very faint.
My lips were done in a natural tone that perfectly matches the inside of my lips. The lip color fades fairly quickly, and I have it retouched every year to maintain the color. And, yes, tattooing the lips is the most painful procedure I've ever endured. After the first time, when I didn't know how excruciating it would be, the technician only used numbing cream, which didn't seem to work at all. Subsequently, I go to the dentist and have him numb me up completely before the tattooing. I never have to bother with lipstick or lipliner ever again (unless I want to). During the day, I just use clear gloss or chapstick. I'm very glad I had it done.
I would not have just lipliner done, though. Have the entire lips tattooed. It will look more natural and you won't have to worry about keeping lipstick on.
Before committing to the procedure, do research on the technician, ask for references, and ask to see photos of her work. Communication is also key. Make sure she understands exactly what you want.
