A fruitless shopping mission in Causeway Bay recently left me questioning the entire theory of supply and demand.

The product I desired? Tampons.

Before you start screaming "ewww" or "that's disgusting" over your half-eaten brunch, A) I don't care, and B) turn the page. Because these words are not for you, but for all those women who have wasted precious time traipsing this city looking for a place that stocks these necessary items that help deal with one of the most natural things in the world.

That so-called "convenience store" 7-Eleven was everything but convenient. If I wanted a Hello Kitty backpack, a mug with the mug of Elsa from Frozen on it, a USB flash drive, a selfie stick or cables for my mobile phone, then I'd have hit the jackpot. But tampons? No luck.

A few doors down was an old-school dispensary selling an array of traditional Chinese medicine ingredients, from trippy-looking mushrooms to deer hooves, but not the one thing I - and thousands of other Hong Kong women, surely - needed.

Next stop Mannings. This normally trustworthy emporium of cosmetics, vitamins, bust-boosting creams and other essential products "catering" to women's needs also failed to stock the T word.

This problem has existed in the city for years and while it's improved slightly, with tampons now stocked in some Watsons outlets and a few supermarkets, they are still in short supply. What's the deal Hong Kong - are we too embarrassed to put these little essentials on the shelves?

And as for why they are so expensive, well, I'll leave that rant for another month …