This article is from the Piercing FAQ, by Anne Greenblatt with numerous contributions by others.
4 to 6 months
This piercing is made through the tissue over the bridge of the nose.
This piercing must not be made too deep to avoid piercing the blood
vessels and nerves that are found on either side of the bridge. The
piercing is usually 3/8" to 9/16" wide. This piercing has a high
incidence of migration and rejection, particularly if the tissue is
shallow or flat.
An infection of a bridge piercing should be treated very seriously
because of the close proximity of the sinuses. For this reason, some
piercers do not perform this piercing.
Initial jewelry: Straight or curved barbells in 14 to 12 gauge and
7/16" to 5/8" in length; the barbell should be at least 1/16" longer
than the width of the piercing. Captive bead rings in 14 to 12 gauge
and 1/2" to 5/8" in diameter. No more than 1/4 of the ring should be
through the piercing. A ring which is too small in diameter will often
cause the piercing to migrate or scar.