When can I shave my head following scalp micropigmentation?

Every doctor has a different post-care regimen. It is always a good idea to ask your doctor. In general you can shave the same day as long as you are not using shaving cream.  Dry shave is ok.

Scalp micro pigmentation is a highly sought after procedure to cover bald spots by mimicking hair follicles. It is more popular among men, and at times, male patients may decide to go for a bald look after the procedure.
Right after scalp micro pigmentation the scalp is going to be tender due to the delivery method of the ink via needles. Therefore, it is advisable to allow the scalp heal before trying to shave the head as the blade can cause more irritation.
The healing time will depend on the brand and variety of the ink used along with the surface area of the procedure performed. Patients are typically advised to wait a span of 7 to 10 days before shaving their head. The physician may recommend a dry or wet shave depending on your medical profile.

I typically have my patients use clippers for the first week (first clipper session at day 3). Shaving with razors I ask to wait until right before their 1 week follow up to reduce irritation, knicks, and the potential to traumatize the skin. Nikki D. Hill, MD

You can shave your head 4 days after the procedure is done.  Shaving is a favorite style for some people with SMP as you can see from the web site below