Should I use it twice a day? Or if I forget at night, can I apply it the next morning?

Latisse should only be used once a day at night.  If you forget a night, don't worry about it and don't double up the dose the next day, just apply it the next night as usual.  You may not see optimal results for 3-4 months so don't give up hope!

Latisse should only be used once a day in the evening.  If you should forget to apply at night, I would recommend just skipping a dose for that day.  It can take a few months to see the results, so it is not unusual that you would not see any noticeable result 6 weeks after you began.  

Hello,We recommend that our patients use Latisse once daily for visible improvement in lash length, color, and fullness. Using twice daily will really not give you any additional benefit (and it will cause you to run out of product more quickly.) I would also like to address your comment where you mentioned you had been using the product for 6 weeks. Typically, patients see the most benefit begin to appear around the 3 month (12 week) mark. Keep using, and thanks for your question!Be well,Dr. Hobgood

Hi ngocminh, thanks for your question. Use Latisse before bed. Most people see an improvement in lash length and thickness in 2-3 months of consistent use. Best of luck.

20 % of users of Latisse don't see results. However, I would not recommend making that assessment until a given patient has used for at least 12 weeks. At 6 weeks, there certainly are a proportion of patients that don't have much in terms of results. Waiting is a good idea to be certain if a patient is a 'responder' or not. 

Latisse is directed for once a day use.  Some patients do not see results until 8-12 weeks.  At that time you can maintain your lashes by continuing your use at once every other day or every three days.  

You only need to use Latisse once per day. You can either apply it at night or in the day time before makeup. But just make sure it is to clean, dry lashes. You only need to apply it one time daily and it will not help to do it more often. Optimal results are seen after 16 weeks. "This answer has been solicited without seeing this patient and cannot
be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."