Posting this because the summary going around does not say what the paper says, and the difference matters for how people here are using it.
This is telogen effluvium and the trigger is the rate of weight loss rather than the molecule. Rapid loss pushes a large fraction of follicles into the resting phase simultaneously; they shed together two to four months later, which is why the shedding starts long after the loss did and why people misattribute the timing. It is self-limiting, and regrowth follows once the rate slows — the follicles are not damaged.
Where I think it is weakest: the completion rate deserves as much attention as the headline, because a large effect among those who finished is a different claim from a large effect among those enrolled.
What would genuinely help is knowing whether the shedding is the drug or the rate of loss, and when it stops. Tell me what I have not thought of.
Note on sourcing:
Figures above are from the primary publication rather than the press summary. If a number here disagrees with one you have, post yours and we will work out which of us is reading a secondary source.