The suggested dose of 3,000mcg is a recommendation for adults.
We advise you to have your levels checked occasionally and, of course, you can adjust the number of drops you take to address a deficiency on a shorter term basis, or lower them a little if levels are fully replete. Vitamin B12 is a very safe vitamin.
The absorption rate is up to 98% for liquids vs pills. When taken sublingually, the vitamin enters the bloodstream within 2 minutes.