Botox was accidentally injected into a vein on side of my temple, had massive bruising afterwards. Will this cause damage?

The bruise will subside in a little while but after that, there will probably not be any issues.  Make sure to call your doctor and have them note that it happened so there is a record of it but you should probably be fine in a few days’ time. Hope this helps, Dr. C!

Unless a provider is unaware of injecting large volumes of Botox in a vein, which is not common, the needle injecting a vein may cause bruising, swelling and tenderness but they are all temporary. Systemic effects of Botox from intravascular injection are extremely rare.The information provided in Dr. Shelton's answer is for educational purposes only and is not intended to constitute medical advice.  The information provided should not be relied upon as a substitute for consultations with a qualified health professional who may be familiar with your individual medical needs. 

You should not have permanent damage from Botox injection that caused bruising. The bruising will eventually go away.

You should be fine in 7-10 days when the bruise goes away. Many patients bruise with Botox.  Best of luck to you. 

Thank you for sharing your question. You should not have any long term problems from being injected with Botox even if a vein was hit. The bruise should improve over a week or two. Make sure to see experienced injectors for your treatments. Good luck,

If while you are being injected with Botox your injector hits a vein, you will likely have a bruise and some swelling for a short while. Other complications are very rare.. This is due to the fact that the amount of Botox being used is very minimal for these procedures. 
Your bruise should heal itself within a few days time. 

Accidentally injecting Botox into a vein on the temple should not cause any permanent problems.  The area may be bruised for several days, but this should resolve completely over time.  There should be no other long term effects.  

Botox very unlikely to cause vascular or vein issues other then the bruising you have experienced. I would recommend applying topical Arnica and/or Vitamin K cream to the bruised area which will help clear the bruise much faster then letting it dissipate on its own. You can also pre-treat with arnica for a week prior to your next Botox treatment to help prevent and lessen bruising which is the most common side effect with a facial injection! Arnica is available over-the-counter from various herbal or skin care companies, many online. Good luck!

Botox is one of the leading cosmetic treatments done around the world. Common cosmetic usages include wrinkle reduction and Hyperhidrosis. Bruising at the injection site is a common side-effect but will resolve itself overtime. Typically, most patients can return their normal activity shorty after treatment. As a precaution it is recommended that patients stay upright for 4 hours, and additionally no exercising for 24 hours post treatment. Always discuss common side effects prior to your treatment with a Board Certified Dermatologist.

Other than the initial bruising in the temple, there is unlikely to be any side effects from injecting Botulinum Toxin into a vein. Botox doesn't tend to cause vascular problems like dermal fillers so is safer in this area. The doses used from 1 injection are also relatively small.
If you are concerned about any symptoms that develop get back in contact with your doctor who did the treatments, as they can easily check it out for you.