New question

I am wondering coming off of Klonopin for 15 years , 1 mg a day. (In last 5 years )why does it take so long , if the half life is 30 to 40 hours. It has been 3 weeks , still in withdrawal.

Can someone explain this to me?

Welcome to BenzoBuddies!  We are glad you decided to join us.  You'll find a lot of support and information on this forum, which is the only one of its kind online.  Unfortunately, the effects of benzo withdrawal go on well after the drug is out of your body.  For details on this, please read the "What is happening..." Link below:

http://www.benzobuddies.org/forum/index.php?topic=66397.0

For those starting a taper, we generally recommend starting out at a rate of 5 to 10% every 10-14 days, then adjusting the taper to suit your own needs.  Note: very short term users may be able to taper faster.

Withdrawal symptoms, which vary widely but commonly include anxiety and insomnia, often occur during a taper, but these are temporary and will get better in time.  In general, first tapers are easier, but cold turkeys or multiple withdrawals may be more severe and longer lasting.  Here are a few links to get you started:

The Ashton Manual, a concise reference for tapering and symptom issues.  Chapter III contains excellent descriptions of common symptoms such as muscle issues, anxiety, and hyper-awareness

PostWithdrawal Support

Once again, welcome!