Is it normal to get very sleepy while breastfeeding?

I am not sure if it's just me, but this is my second born I didn't get the luxury to breastfeed with my son but my daughter loves breast milk so much til she is literally drinking formula and spitting it out at 2 weeks. But every time I am feeding I find myself getting so sleepy I take my milk thistle pill day and night and my fenugreek as well along with my vitamins but it's only when she's feeding I slip into a deep feeling of sleepiness 🤷🏽‍♀️ is this happening to other moms out there breastfeeding or is it just me being a super tired mom..