Can Botox cause tightness, heaviness, tension headache right after Botox injection and continue for over a week?

Botox can sometimes cause headaches in a few people with poor or improper injection technique.  I suggest speaking to physician if it is not getting better.  This is not common.  Best, Dr. Emer.

Some patients report a sensation of heaviness in the area that has been treated with Botox®. This may be related to a weakening of the treated muscles. If this persists or worsens, you should seek an evaluation by your doctor who performed the injection.

Sometimes when too many
units are injected, especially in the forehead, you can experience
your symptoms. Although uncommon, these symptoms usually subside over 1-2
weeks.

There is a wide range of variability in the doses required to correct muscle contraction in individual patients.  That is to say, the same condition in 2 different patients may require markedly different dosages of drug.  It may be that you require a lower dose of Botox than most people.  I would to discuss your outcomes with a highly experienced injector to see how you can achieve best outcomes in the future.

Thank you for your question. It is possible to experience headaches after a Botox treatment. If the problem persists after 2 weeks, schedule an appointment with your injector to discuss treatment options. Best,

This side effect is uncommon. However, it does happen frequently enough in specific patients every time they have a treatment. In my opinion is an individual response. In most cases the effect lasts 1 to 2 weeks. I have been referred a few patients with your symptoms that have lasted up to 5 and 6 weeks. 
Dr Joni Feldman

What you describe is not uncommon.Two things come to mind.The most common reason for headaches after Botox is the provider accidentally touching the periosteum or covering of the bone with the tip of the needle.This is most common when shooting the forehead.The heaviness and low-set brow you are experiencing is simply the effect of treating the forehead or frontalis muscle. The function of this muscle is to raise your eyebrows.Since Botox injections cause an effect opposite of the function of the muscle, injecting the frontalis or forehead muscle will cause the eyebrows to drop.Patients with low-set brows or heavy eyelids are particularly prone to disliking this aspect of the treatment.In the future, consider treating only frown lines and crow's feet.While you have little control over the technical injection itself, the provider has to make an effort to not "bump the bone" with the needle tip.There are many techniques on making Botox injections less painful both during and after the procedure.These include using powerful topical anesthetics and sharp needles of the highest quality, which need to be exchanged multiple times during a procedure. I will often use four to six or even eight needles for a single Botox treatment session.A dull needle will give a crunching sensation. If you've ever experienced this during a Botox treatment, the needle has become dull and needs to be replaced.As the Botox begins to wear off, your concerns should dissipate.Best of luck,Mats Hagstrom, M.D.