Have to Blend Forehead Botox Treatment with Glabella Treatment?

You can get the forehead and the glab areas done separately but it is less expensive if you do them together. Cost is usually $300-350 for 1 area and $500-600 for 2 areas whether it is botox or dysport and lasts about 3-4 months.

The key to good results with Botox to the forehead and glabellar region is recognizing that the two muscle groups pull your eyebrows in opposing directions.
Treating your forehead (frontalis) muscles in isolation can alter the position (lower them) of your eyebrows. If your brows are in good position (no ptosis), try a very light Botox treatment to the upper forehead (no more than 6-8 units) and observe its affect on your eyebrow position over the ensuing weeks.
Your best bet with Botox is to have the glabella, frontalis and upper/lateral orbicularis muscles treat in concert. Such a treatment plan might even elevate your brow position, which is nice.
Seek out a clinic staffed by a board certified plastic surgeon for your Botox needs. A good Botox injector will thoroughly examine your face at rest and during movement and design a treatment plan that is tailored to your individual musclular anatomy and brow position.

If you want to try to treat the forehead only you need to be with a very experienced injector.  Treating the forehead alone can give you a very heavy brow and flat eyebrows even with some of the most experienced board certified physicians.  Treating the central area between the eyes (the glabella) is what gives you that eyebrow lift.  My advise is to put at least a little in the glabella area, but that being said you can try forehead only and add the glabella in 1-2 weeks if you feel flat or heavy in your eyebrows. 

You can certainly treat the forehead lines by themselves and not treat the frown lines. You may still want to put a small dose of Botox into your frown lines as a preventative treatment to prevent needing higher doses there in the future. More and more, we are using Botox not just as a treatment, but as a prevention so that lines/wrinkles don't "etch in" which is much harder to treat.

Your forehead can be treated on its own, but make sure you see an experienced injector so you do not develop lowering of your eyebrows.  When your frown lines are ready again for treatment, your forehead should be reassessed as well. 

The Botox treatment can be performed on any of the three muscle groups on the forehead. It is the patient and the surgeon’s preference as to which groups of muscles are injected. The corrugator muscles are cause the scowling and the frontalis muscles is what causes the horizontal lines on the forehead from raising the eyebrows too much. Each one of those can be done independently or together with Botox and the treatment lasts approximately four to eight months depending upon the individual.

Sometimes forehead and glabellar Botox injections should be separated by two weeks depending on the patient anatomy and whether those areas have been treated previously in that patient.

Botox at best lasts 4 to 6 months. So if you are going to divide up the treatments the area last treated will be the last to be in need of treatment. Or the first treated will last the longest. Or WHAT THE HECK just do the treatment at the same time. LOL Regards.

No, you certainly don't "have" to have your forehead and glabella lines treated at one time. The reason most people will suggest it, however, is that if you knock out the forehead muscle (frontalis) the glabellar movement may appear compensatorially stronger, accentuating your frown lines. If budget is a concern, you can certainly have your forehead treated first, wait a week or two, and if you are not happy with your frown lines at that point you could have them treated separately.
Best of luck,
Dr. Rupani

While you don't have to have the glabella and the forehead treated with botox together, be aware that the forehead muscle (frontalis) act to lift the brows while the glabella muscles (corrugators and procerus) have an opposing force which pull down the brows. Many people like the subtle "lift" that they get from treating the glabella, especially women as it gives them a more awake, refreshed appearance.
Depending on how extensive the forehead lines are, it can be risky to have them treated only without the glabella as it can drop your forehead and brows making you have a "angry" appearance. I would discuss these issues with your doctor and one way around this can be to have you forehead treated more conservatively and higher up so that it has less potential to drop. Then, if you are happy great, if not you can either have it touched up a bit more or have the glabella treated to counteract any dropping effect in two weeks.