Decide what to keep, wear, or replace.

This is a real gray area.

Some vegans avoid all leather, wool, silk, and down, including secondhand. Some keep what they owned before going vegan. Some buy secondhand animal materials because they are not creating new demand. Some draw different lines by item.

There is not one clean answer that settles every closet. The point is to understand the tradeoff and make a decision you can live with consistently.

It is also okay for your answer to change by category. You might keep an old wool coat until it wears out, avoid buying secondhand leather bags, and choose synthetic dress shoes for formal events. A standard can be specific without becoming a performance.

The two honest arguments.

The case for secondhand is that the item already exists. Buying it does not send the same production signal as buying new leather or wool, and using what exists can reduce waste.

The case against secondhand is that wearing animal materials can still normalize them, keep them desirable, and make your own line feel blurry. For some people, that is reason enough to avoid them.