Injecting Botox properly requires more skill than people tend to think. It’s not as simple as going after the muscles that are causing wrinkles to form. The skilled injector knows too much Botox to the frontalis muscle (central forehead) can drop the brow, because that muscle is responsible for lifting the brows, and for creating those horizontal lines across the forehead. Typically, you want to balance the amount given to that muscle, and the amount given to the glabella (area between the brows, creator of “11s”) so that you are not “freezing” either of these muscles, but rather balancing their strength so they are both relaxed, but the brows are either slightly lifted or at the very least not dropped. This is similar to the idea of feathering a clutch in a manual transmission car – there’s a sweet spot, but you have to learn how to get there with experience and finesse The fact that your muscle between your brows has seized up in a Charlie horse and is giving you a headache tells me this muscle is working overtime to try to compensate for your forehead muscle that has been knocked out. This suggests you were given too much Botox in the forehead muscle and not enough in the glabella. Even an experienced injector can do this when they are injecting a patient they’ve never treated before, because everyone’s muscles react a little differently. Typically, this is why experienced injectors go light on their first treatment of a new patient, and ask the patient to come back in 2 weeks for a touch-up. That 2 week window gives the Botox time to kick-in, so the injector can fine-tune the results at the follow-up appointment. Once you’ve established the proper dosing, it gets easier to retreat with accuracy and ease. Were you my patient and you returned with the forehead completely knocked out, I would have injected your brow to try to balance out the muscles, just as it sounds like he/she did. It sounds like your doctor did what any skilled injector would have to try to balance things out at the follow-up. Did they possibly inject a little heavy-handed to begin with? Maybe. Are you more sensitive to Botox than the average person? Maybe. I would let them know that you wanted more of an explanation at your next visit, but from what you’ve detailed, I would trust that they are following the standard of care and are indeed much more knowledgeable than a lot of injectors out there. If your headaches are persistent, I would call your doctor and possibly see your general practitioner as well.