I have completed 6 months course of isotretinoin. Can I repeat the dose again? If yes, how many times can I repeat it?

Thanks for your question.  You absolutely can take accutane again if you feel you need further help with your acne.  Some recent studies have shown that when younger patients take the medication, they will need to repeat it if their acne was very severe at a young age, or if they didn’t have an adequate dose the first time.  You might want to use a topical retinoid for awhile, such as Tazorac or Retin-a to see if you improve on those types of medications, but don’t hesitate to consult your dermatologist if you want to consider another accutane course.
Best of luck!

Yes, it is possible to retake Accutane.  I recommend waiting 3-4 months for the effects of the initial does to process in your body.  Then you can have a new discussion with your doctor about retaking Accutane.