His brilliant response has since caused the post to go viral with more than 31,000 likes.
"Blackcurrant or lime?" he asked, referring to the purple and green packaging.
"Looks like he's a legend," one person wrote.
"Love that he think of them as flavours!!" another commented on the post.
"Brilliant response from your dad but nice to see how a father didn't hesitate!" a third said.
"This! It's amazing you are that close to your dad to feel comfortable to ask him. He is a legend!" a Twitter user commented.
However, not all of the hundreds of people who commented found it funny.
Many branded the request "awkward" and "strange" for someone to ask their dad to get them female hygiene products.
However, Niamh hit back, saying "For all the people getting wound up about asking my own dad for pads. 1. He's only ever lived with females, my sister, my mum, his sister, his mum.
"2. I was in work until 5 shops close at 4 on a SUNDAY I don't drive, neither does my mum
"3. it's 2019 not 1969."
Others came to her defence, saying those who have an issue with something like this "confuse me".
"Is Niamh supposed to just hold her period in until the shops open on Monday??" one woman said.
"You really don't need to explain why you asked your dad for pads," another added
"You dad is tops for doing this I get them all the time for my misses never an issues some people live in the olden days."
For those wondering, Niamh chose "blackcurrant".
It's not the first time a dad has been hailed a "legend".
A similar situation unfolded in June, this time involving a daughter's "butt-cutting shorts".
You wear yours out in public? I will wear mine! Parenting 101! Alison Wasson Hilley
Posted by Jason Hilley on Wednesday, 12 June 2019
The father was crowned dad of the year for pranking his teenage daughter with a hilarious "Parenting 101" fashion lesson.
"You wear yours out in public? I will wear mine! Parenting 101!" the funny dad said in caption alongside a video he shared to Facebook.
In the hysterical 75-second clip, which has since been viewed 24 million times, Jason and his young son burst into the girl's room for an impromptu schooling.
In the days since, the legendary family moment has gone viral, with more than 144,000 shares, 11,000 likes and 6700 comments to date.