Is it possible to add drawstring to puffy hood with only elastic?

Should be very easy to do that.

dk…….thanks for the reply.  I just want to make sure that this can be done before I buy it.  Have you done this or seen it done?

Yeah, I’ve been meaning to do that myself to my Hadron anorak hood. There’s an old thread somewhere, in which others assure me I can.

I have not done that exact thing, but adding a casing for a drawstring is quite a simple thing, and I have done that.  They could either remove the elastic if it’s on the outside, or sew the casing over the edge/elastic, while stretching it.  If you are particular about exact color or fabric match for the casing, that might be more of a hassle, but still possible.

If you are going to a regular tailor, you might even want to bring in an example of a hood with drawstring/toggles, since it’s remotely possible they might not be familiar with outdoor gear.

It’s only sewing. Anyone could do it.

But I will add suggestion: make it an open-ended tunnel, and thread some very light bungee through it. Several reasons:
Ordinary elastic last a few months and rots.
If the bungee is replacable, that makes life easy.
Put a tiny cord lock on each end so the elastic can be adjusted.

Cheers

If the hood has a Lycra edge binding  (the one in the O.P. looks like it might), it’s often possible to do a no-sew shockcord drawstring. The lycra binding is often tubular if only stitched on the edge. Forming a ready made channel for a cord.

I did this to the hem of my Uniqlo Ultralight down hoody.

Method:

Thread the end of some 2mm shockcord onto a darning needle, fold a few mm over and stitch together.

Decide where you want the cord to exit the hood edge, and wiggle the needle through the weave of the Lycra edging to its interior. Ease the needle around inside  the hood rim to the other side (drawing the shockcord through behind) and then force the needle to exit at the opposite side to the start point.

Pull cord end out, remove needle.

Add mini cordlocks to each end and cut cord to length and Knot.

Done.