Hi jagfel! Presuming you're FtM and "just started" (when?) testosterone... Testosterone is an anabolic hormone. It will cause some nitrogen, sodium and water retention. That's why some people may have water retention (edema) during the first few weeks of TRT which can be reflected as increased weight or ankle and foot swelling. That may be an explanation for the feeling of smaller shoes that you mention. Try to sleep with your legs raised (couple of pillows under the bottom of your mattress) and see if in the morning the shoes feel "bigger" again - that would be a clue to fluid retention. Anyways, there are other possible explanations, so if it's of concern to you, do not hesitate to consult your physician.
Hugs, Sarah
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