Sounds like 'var-eh-nik-lin'

Varenicline is used to help people stop smoking. Find out how to take it safely and possible side effects. Varenicline is also called Champix.

Type of medicine Also called
  • Medicine to stop smoking   
  • Champix ®

 What is varenicline?

Varenicline is a medicine to help adults stop smoking. It works by blocking the effects of nicotine in the brain. Varenicline can help to reduce craving and withdrawal symptoms that happen while you give up smoking. Read more about how to quit smoking.

In New Zealand varenicline is available at tablets (0.5 mg and 1 mg). 


  • Varenicline is usually taken for 12 weeks.
  • When you start taking varenicline, the dose is slowly increased to lower the chance of side effects such as nausea, and unusual dreams.
  • Start varenicline 1 week before your target quit date. This helps build up the medicine in your body while you smoke for a few more days.
  • During the first week: take 0.5 mg once a day for 3 days, then increase to 0.5 mg two times a day for 4 days. It is okay to smoke during this time. 
  • After the first week: stop smoking on the quit date then take 1 mg two times a day for the rest of the 12 weeks.

My dose

Varenicline is usually taken for 12 weeks as follows:

Dates Varenicline dose
Quit date: ________________

Start varenicline 1 week before your quit date.

Date: ____________to _________

(3 days)

  • 0.5 mg once a day for 3 days
Date: __________ to _________________ 

(4 days)
  • 0.5 mg two times a day for 4 days
Date: __________ to ________________

(11 weeks)
  • 1 mg two times a day for 11 weeks

How to take varenicline

  • Swallow the tablets whole with a full glass of water.
  • Take varenicline with food. This helps to prevent stomach upset.
  • Limit drinking alcohol while you are taking varenicline. Drinking alcohol while taking varenicline may increase the risk for mood changes. 
  • If you forget to take your tablet, take it as soon as you remember that day.
  • But, if it is nearly time for your next tablet, just take the next tablet at the right time. Do not take double the amount of tablets.

Precautions before taking varenicline

It’s important that you tell your doctor or pharmacist before you start using varenicline if you:

  • have epilepsy or have ever had epilepsy, a seizure (fit or convulsion) or an unexplained blackout
  • have a history of a psychiatric illness including depression
  • are pregnant or breastfeeding.

Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

Possible side effects

Like all medicines, varenicline can cause side effects, although not everyone gets them. Often side effects improve as your body adjusts to the new medicine

Side effects What should I do?
  • Indigestion
  • Feeling sick (nausea)
  • Stomach discomfort
  • These are quite common when you first start taking varenicline.
  • Try taking varenicline with food.
  • Drowsiness
  • Tiredness
  • Weakness
  • These are quite common when you first start taking varenicline.
  • Be careful when driving or using tools until you know how this medicine affects you.
  • Limit alcohol intake.
  • Tell your doctor if troublesome.
  • Difficulty sleeping
  • Sleep disturbances
  • Abnormal dreams
  • Tell your doctor if troublesome.
  • Agitation
  • Feeling anxious
  • Mood changes
  • Depression
  •  Tell your doctor immediately or ring HealthLine


Varenicline may interact with a number of important medications and herbal supplements so check with your doctor or pharmacist before starting varenicline or before starting any new medicines.

Learn more

Medsafe Consumer Information Sheet Champix
New Zealand Formulary Patient Information: varenicline 
For more information on how to quit smoking, see the Quitline website

Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland