Every body is unique and individual results may vary! It’s hard to specify a standard time for everyone. Beginners may feel comfortable upside down for minutes at a time and some long-time yogis may only want to invert for a few seconds 😉
We recommend everyone begins by inverting several times a day, but only for a few seconds at a time. Gradually increase the length of your inversions over a week or two. Go slow! There is no rush. Utimately, it's up to you to build awareness by listening to your body.