Did Roman legionaries use spiderwebs to speed wound healing? Possibly, but not for the reasons suggested in the video below.
The video suggests that the vitamin K in spiderwebs would have stopped bleeding. Although vitamin K is essential for making clotting factors (and stopping bleeding), there is no evidence that spiderwebs contain any meaningful amounts of vitamin K, and any tiny amounts of topical vitamin K on spiderwebs would not be useful for controlling bleeding anyway.
Were spiderwebs used for wound care? Pliny the Elder mentions the use of spiderwebs in Naturalis Historia (Chapter 36):
https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.02.0137%3Abook%3D29%3Achapter%3D36&utm_source=chatgpt.com
So, how could spiderwebs potentially assist in wound care?
Spider silk could form an extremely fine mesh. When pressed onto a wound, it acts like primitive gauze:
The mechanical lattice effect works because spider silk forms a dense, flexible mesh that lightly adheres to the skin and immediately traps blood at the wound surface, giving platelets a stable scaffold to cling to while the body initiates clot formation. In practice, this makes the web function like an early form of gauze, slowing blood flow long enough for a natural clot to form.
Also, some webs might have harbored mold or dust with antibiotic properties, and spider silk proteins themselves have rudimentary antimicrobial effects. This might have reduced infection, making the treatment appear more effective overall.
Contrary to the video, spiderwebs would not have stopped bleeding like an ancient styptic. But spiderwebs would, at least, be better than a dirty rag and probably wouldn’t adhere to a wound.