How long does it generally take to remove a tattoo?

The first thing I would like to address is the four week intervals. I do not recommend repeating tattoo removal treatments earlier than 6 weeks. This has to do with physiologic healing time: it takes 6-8 weeks for tissue to recover from moderate to severe injury and laser tattoo removal can fall into the moderate injury category. If the practitioner is using low energy to decrease the recovery time then you really aren't getting the treatments you should be getting. Second, it is impossible to know exactly how many treatments it will take to remove your tattoo to your satisfaction, so this is guess work and you should expect that it will take more treatments and hope that it will take less.

I actually recommend waiting closer to 2 months between tattoo removal sessions, to give your body time to heal and also time to eliminate the shattered pigment. If you need 7 sessions, then your time line would be closer to a year to a year and a half. A board-certified dermatologist who has PicoWay will be able to remove your tattoo most effectively.

Hello and thank you for your question.  Without knowing what specifically what type of treatment you  are referring to, it is difficult to respond to what you were quoted.  What I can tell you is that in our practice we use the PicoSure laser by CynoSure, which is a very advanced medical laser that uses trillionths of a second pulses to target ink particles.  This is so powerful that the ink shatters into dust-like particles, which are more rapidly absorbed and eliminated naturally by your body.  We typically recommend a series of 4-7 treatments (each case is individual and different), and generally treatments should be spaced 8 weeks apart to allow your body the time it needs to eliminate the shattered ink.  Thus the cycle for maximum elimination can be up to a year.  I always recommend seeking out a couple of consultations to find the practitioner that you feel is the most skilled and that you are most comfortable with as this is a long term relationship and process with your clinician.
All the best to you!

You ask an excellent question, and you'd be surprised how UN-straightforward the answer is.
The ideal timing between laser tattoo removal treatments is controversial, mainly because it hasn't been studied very well. But this much practitioners mostly agree on: Longer is probably better. Currently the minimum time is considered to be 6 weeks, making your every-4-weeks scenario unworkable. I have been recommending longer intervals (8-12 weeks) after observing the results of several patients who took pregnancy breaks and came back looking like they'd had 2 or 3 treatments while they were away. It appears that longer intervals might translate to fewer visits required, at the cost of a longer tattoo removal. In my practice, patients in a hurry may come back every 6 weeks, and those on a tighter budget or in no hurry can go longer.
So, to answer your question, you might get more results out of those 7 treatments if you allow maybe 2 years to remove that tattoo.
Please share your tattoo removal story there on Realself as it unfolds! And good luck!