Robin laying on the couch holding a large stuffed cat to her belly. There is a hot water bottle inside the cat. You cannot see her face.

You & Your Undu: Firsthand Experience from a Founder and Tester


If you’ve ended up here, chances are high that you experience menstrual pain. I’m so sorry! 

The good news is, you’ve done some research (or a super sweet person in your life has sent you our way!) & you are one step closer to feeling some relief. 

Also -- I feel your pain! I’m turning 29 & have experienced horrible cramps since getting my period at age 11. 

This means that for 1 or 2 days every. single. month. I miss out on everything. From school & work to exercise & social time. I’m curled up in bed eating ALL of the treats & hugging my hot water bottle (whom I affectionately call “Bertrand”). 

I love Bertrand… but I can’t exactly leave the house clutching a massive fluffy cat with a hot water bottle inside. (Did I not mention the fluffy cat covering before?) 



I react strongly to medications & appreciate things that are easy to use. So, sticking with the time-proven pain-relief method of applying external heat is the way to go for me! 

Enter, undu.! 
We figured out a way to create a super thin, wearable hot water bottle (that you don’t have to fill!) so you don’t miss out on life… no matter where you are in your cycle! 

It’s as easy as making a cup of tea! & by applying the Undu Original Heat Pack as soon as I begin feeling cramps, I can greatly reduce the intensity & amount of time I’m in pain. Instead of agony for 2 days, it can be as little as discomfort for 2 hours. 

The portability & easy heating method means I can bring it with me for on-the-go relief anytime, anywhere. The yoga studio, cafe, work, camping… 

I’ll expand a bit on “Roll it, heat it, wear it!”

When our heat packs are first made, they may be a little stiff & need some warming up. I usually do this by running the pack under hot tap water for a few minutes, until the pack is soft enough to roll. 

Some tap water doesn’t get quite hot enough, or maybe you don’t want to run water for so long! Another option is to let the pack sit in hot water in a casserole dish, salad bowl, or other heat-safe vessel you have on-hand! [Points for creativity!]

Once the pack has been softened, it’s easy to roll it up & stick it in a mug! Initially, our heat packs were a bit smaller, so one round of boiling water would perfectly heat the pack.  We’ve increased the size (based on interviews & product testing with folks like YOU!) & it now takes 2 rounds of boiling water in a mug.

When I’m at home (read: all the time, because COVID), I typically have a pot of water heating constantly on the stove on days I’m cramping. Much like sanitizing my menstrual cup, I simply boil the heat pack for a few minutes on the stove, remove with tongs, give it a quick dry, and away we go! 

You could also use any heat-safe vessel and pour boiled water from a kettle onto it -- whatever makes you feel most comfortable! We like to have options & there are a couple more ideas up our sleeves to make our packs easy to heat in every situation! (get excited!)

The heat will last longer if the beeswax mixture completely melts. It’s easy to tell, because the pack will change colour & become translucent! It’s your own little science experiment! 

I typically wear our ‘Keep It’ Brief OR place the pack under a pair of leggings & over a tank top to start. I usually wear the pack on my lower belly, but I sometimes place it on my lower back. Eventually I remove the tank top layer so the pack is directly on my skin. Applying pressure feels nice sometimes, too! Everyone has different sensitivity levels, so explore to find what works best for you [& let us know]!




I feel relief for up to 40 minutes! I find the heat comes in 3 parts, like any good story. The beginning does not want to be overlooked, & shows up with some immediate intense heat & relief! The middle is the star of the show with even, constant heat for the longest time (the pack will be super mushy & start to become opaque again). The closer of the show is a gentle, comforting heat that feels like a gentle hug from a loved one. Sometimes I touch the pack with my hand at this point & am surprised that it’s still warm! The body becomes used to it, but the pack is still working away. 

It’s super easy to reheat & you can use it as many times as you need!

I’ve gone on 2-hour walks, practiced yoga, cycled through the city, worked, napped, had a glass of wine… all while wearing my heat pack! I’ve even forgotten I’m wearing it!

Once I’m finished with my pack for the time being, I roll it up & keep it in the little cloth bag, next to my bed, for the next time, and the time after that, and so on… for the next 2 decades. 

Our heat packs don’t stop giving… even if they break! Keep your eye on the water when you’re heating up your pack & don’t use it anymore if you see oil in the water. You can cut open the pack, squeeze the beeswax mixture into a jar and reuse it!

[Send us an email, too!]

In a world that asks so much of us & wasn’t designed with us in mind, I hope that we can bring you more options, more comfort & more dignity to let you do you!

Let’s treat ourselves & Mother Nature kindly. 

xx Robin


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