There are possible side effects of microneedling, both at home and in an office. Skin is individual and unpredictable! While almost all patients will experience collagen regrowth in response to microneedling, for some people it can come along with some  negative side effects like hyperpigmentation (documented in much of the research on microneedling for people of color), tram track scarring (cite), and granulomas (cite).

These side effects are relatively uncommon, but they do have the potential to be permanent, or to require an expensive intervention to treat. And the fact that they’re uncommon doesn’t really help any given individual; if only one percent of the population gets hyperpigmentation after dermarolling, but you’re part of that one percent, then that doesn’t really help you very much or make you feel any better! And, while we can make some predictions about who might have a negative outcome from the dermaroller, you won’t really know how you, individually, will react until you’ve tried it out. That’s why it’s so important to patch test your dermaroller.

But I don’t want to patch test!

If you happen to be one of the people who are going to have an adverse reaction to the dermaroller, it’s better that it happen to a small part of your body rather than your whole face after you jumped in and did a full treatment.

Nobody likes to patch test. Especially after buying a skincare tool that has the potential to drastically change your skin, you want to get moving! Especially with microneedling, with the long intervals between treatments and the delayed (but amazing) results, it is so tempting to get moving NOW, to feel like you’ve been living with your acne scars or fine lines or hair loss long enough.

But! The possible drawbacks are serious.  Don’t skip this.

Below, I offer three strategies for patch testing: a basic one, a cautious one, and one for people considering in-office microneedling. For all three, there are two ground rules: you must use YOUR OWN MICRONEEDLING TOOL (it’s not a hair dryer, you can’t borrow a friend’s to see if you like it) and you must fully complete the sanitizing steps even if you only used it for a minute. That means that even when you’re still deciding if microneedling is right for you, you have to have at least the dermaroller or dermastamp, the rubbing alcohol and dish soap. Buying a dermaroller in the knowledge that if you have an adverse reaction you’ll need to throw it away kind of sucks, so I recommend the inexpensive pink-and-black ones from Amazon (link to 1.0mm*, link to 1.5mm*).

Patch testing for people with no previous skin concerns

(If you have no history of hyperpigmentation, granulomas, post-inflammatory erythema or any kind of weird scarring patterns, start here.)

Day 1 – use your dermaroller on a small patch (say, 2″ by 2″) on your forearm as directed in my post on how to use a medical-grade dermaroller. The softer, more muscley part of your forearm will hurt the least. If you have used a hyaluronic acid serum* before, you can use that over the treatment area. Don’t use anything else right now. Wait two days, monitoring the patch.

Day 3 – (Only if your desired treatment area is on your face or scalp; otherwise do nothing this day.) If the treatment area looks normal and doesn’t feel hot or sensitive to the touch, try another 2″ by 2″ patch on your face. The jawline is the least obvious if something is to go wrong. Do not choose an area that you hope to treat with the dermaroller, because if you roll part of it today you won’t be ready to roll the whole area again on Day 7. Use your hyaluronic acid serum again, or nothing. When you do whatever your usual skincare routine is, avoid this patch, ESPECIALLY with actives.

Day 7 – Check both of your test areas. If there are no discolorations, spots of lost pigment, changes in skin texture, tram track (scratch-like) marks, scabs, keloids or granulomas, go ahead and start your treatment protocol!

Patch testing for people who need extra caution

(Suggested for people who have a history of red or brown marks that hang around after acne, people who have gotten granulomas, people with the deepest skin tones, or people who have had other undesirable responses to skin trauma. Take the extra time!) 

You’re going to follow the same protocol as above, spread out over a month. This patch test protocol is meant to ensure that you don’t do anything to your treatment area that’s going to complicate the skin problem you’re trying to solve. If you’re going to have a skin problem in response to microneedling, you will see it within a month.

Day 1 – use your dermaroller on a small patch (say, 2″ by 2″) on your forearm as directed in my post on how to use a medical-grade dermaroller. The fuller, more muscley part of your forearm will hurt the least. If you have used a hyaluronic acid serum* before, you can use that over the treatment area. Don’t use anything else right now. Wait two days, monitoring the patch.

Day 10 – (Only if your desired treatment area is on your face or scalp; otherwise do nothing this day.) If the treatment area looks normal and doesn’t feel hot or sensitive to the touch, try another 2″ by 2″ patch on your face. The jawline is the least obvious if something is to go wrong. Do not choose an area that you hope to treat with the dermaroller, because if you roll part of it today you won’t be ready to roll the whole area again on Day 7. Use your hyaluronic acid serum again, or nothing. When you do whatever your usual skincare routine is, avoid this patch, ESPECIALLY with actives.

Day 30 – Check both of your test areas. If there are no discolorations, spots of lost pigment, changes in skin texture, tram track (scratch-like) marks, scabs, keloids or granulomas, go ahead and start your treatment protocol!

Patch testing for people planning to do microneedling in an office

So, a lot of the fuss about microneedling makes it sound like these negative effects happen because people DIY it, but unfortunately, paying the money to get it done in an office doesn’t prevent these adverse effects. If your skin is prone to hyperpigmentation, you might get hyperpigmentation regardless of who’s doing the treatment.

Nevertheless, people do decide to get this done in-office and that’s totally valid. If you want to check and make sure your skin is going to tolerate microneedling without adverse effects *before* you go into the office, you can do so inexpensively with a cheap dermaroller at home. So, the goal here is to buy a $10 dermaroller and make sure your skin likes microneeding before you pay for the expensive appointment that might have a negative side effect. So: hell yeah, get it done in the office if that’s what works for you. But you can test your skin first. I would suggest this as especially important if the reason that you’re going in is for one of these side effects; if you’re going in to have melasma treated, you know your skin is prone to pigmentation issues and you don’t want the treatment to backfire!

If you’re testing in advance of an office appointment, I would suggest following the above protocol well in advance of when you hope to have the appointment. You want to make sure that you have time to cancel (or not book at all) if you suspect your skin won’t respond well. So, choose the protocol intended for you of the two above, ensuring that you have plenty of time to see your test results through.

Next patch test post: patch testing before you use Vitamin C!