How to make your daughter's first period EASY and FUN!CLICK HERE TO READ.
Welcome to Knicked, Welcome to Puberty and Periods SHOP HERE
Terms & Policies
Please see each product page, for individual sizing.
As a general rule, please choose the same size for our period undies and period swimwear as your child's regular underwear size.
Our period underwear is designed here using Australian Child/Youth underwear guidelines. It's important to note that child sizing, also crosses over into women's sizing at our 12/14, so we have also shown this on our sizing charts (on each individual product page) to assist.
We also understand purchasing online can make judging sizing difficult and everyone has a different body shape (literally hundreds of waist & hip combinations) so we have created guides on each product page to help you choose the best fit for each product, or feel free to email our helpful team at theteam@knicked.com.au with waist & hip measurements so we can assist further.
To measure against existing underwear: use the flat lay measurement (side seam to side seam on the waistband) to compare with their current underwear.
Don't panic if you do find you've ordered the wrong size, KNICKED will happily exchange sizing and also cover the postal costs to reship (once per order) as long as underwear has been tried on over clean underwear and returned in AS NEW condition (not washed/worn free of lint/hair/marks), and packaging in original condition.
Please click here for our Exchange/Refund Forms & Guidelines to organise an exchange.
Knicked UltraGuard™ Boyleg Period Shorts
5-Way Super Heavy Protection for All Bodies
Super heavy flow? Side leaks? Need extended sizes?
We've got you covered.
Our Knicked UltraGuard™ Boyleg Shorts are the upgraded version of our popular boyleg design - now with extended sizing up to women's size 20/22, longer crotch design, and full coverage absorption that reaches all the way to the waistband front AND back. With 5-way protection and slip-in pockets, these are your new best mate for super heavy days.
💖 What Makes Them Different?
Unlike regular period underwear, our UltraGuard features:
✔ 5-way absorbency protection (front waistband to back waistband, sides & inner leg)
✔ Super heavy absorbency (50mls) for all-day confidence
✔ Extended sizing (Child 10 - Adult 22)
✔ Longer crotch design with wider protection
✔ 2 slip-in pockets for phone, money or keys
✔ Thin, fast-drying & fitted design
✔ Super soft cotton blend
✔ Boyleg style for maximum coverage
That means total protection from every angle - no more side leaks, just complete peace of mind.
👍🏼 Perfect For:
• Super heavy flow days
• Side leak prevention
• All-day wear under dresses & skirts
• Active days when you can't keep checking
• Tweens, teens & adults (all sizes)
🌿 Designed for All Bodies
Created by a mum, designed for heavier flows.
Our UltraGuard is:
• Super heavy absorbency (5-way protection)
• Reusable & sustainable
• Super soft & comfortable
• Extended sizing for more bodies
• Made to keep you dry and confident
Because super heavy periods shouldn't mean leaks, limits, or missing out on life.
Knicked period undies have always been and will continue to be FREE FROM NASTIES such as PUL'S (plastics) or PFAS (chemicals).


* Our model on the left is wearing a size Teen 12/14 our Plus Size Model is wearing size 18/20 and our model on the right is wearing a size 14/16.
* To measure against another brand of underwear please use the flatlay measurements - side seam to side seam along the waistband.
Tracked postage is $9.95
Express postage is $14.50
Orders over $99 receive complimentary FREE REGULAR SHIPPING
Knicked will exchange item(s) that have not been washed, worn and are in AS NEW condition, we request you submit our Exchange Form within 14 days of receiving your product. Knicked will cover one new shipping cost as a gift to assist - please note: if purchased on sale or outside Australia item(s) can ONLY be returned for a gift voucher to repurchase a new size or style within 5yrs.
Nice Boy Leg undies love the extra wide gusset for confidence and security love the little pockets a great hiding spot for my phone keys ect also purchased a pair for my Thirteen year old daughter she was a little concerned at first but now very happy with them wears them with her school dresses every day when she needs to . We are very happy with them
Very comfy undies. I use a wheelchair so wear these everyday. Well made and super soft fabric o n the skin. Thanks! 💓💓💓
I brought these for my daughter (12). She loves them. She has only worn them as 'back ups'.. but finds they make her feel more secure and comfortable and confident to go about her day.
The pockets on the side are a great added bonus!
Amazing super comfortable and breathable
The Knicked knickers are incredibly well constructed, and really do give 4 directional leak protection. I'm an all over the bed sleeper, a heavy perimenopausal bleeder and I haven't had a sheet soaking for weeks! Amazing!!
Thank you so much for giving the meeting people what they want and need!
My daughter has heavy periods and having leaked in other branded underwear, including the period shorts, she was relieved to find that the knicked period shorts were comfortable and they lasted all day without leaking.She requested I please purchase more of these for her.
I bought these for myself as an adult. I own a lot of period undies. These are great. You forget that you have your period. So comfortable. I felt fully protected with these under my scrubs for work.
Fantastic product. Grandaughter lives the comfort
Great product, great to add to collection
These are my absolute favourites!!! I wear them to school, sport games and overnight. I feel so protected during my period with these shortie-shorts!
Literally bike shorts - they are amazing
When I saw the ad for these I knew I had to buy them for my daughter. She is at her heaviest on the first 2 days and leaks , it’s embarrassing. She has tried different brands to see if they worked but to no avail. My daughter was so impressed when she put these on and is now 100% confident. No leaks due to that wonderful panel. Thank you for thinking outside the box. These are the best for leakage and are comfortable as well. No bulkiness, no leakage, well priced and as she puts it ‘the best period undies/shorts ever!
I loved these ! I have tried a few different brands although there’s never much available for plus sized people and these were so comfy!
I wanted to live in them for the week if I’d had enough pairs.
They were perfect for sleeping in, didn’t have any leaks. Didn’t notice any rolling down.
I’m normally a size 18-20 and the 18-20 were perfect sizing so definitely true to size.
These shorts are just fantastic - super comfortable, I wear them under my clothes for work and have another pair for sleeping - even with my super heavy flow they have never leaked - best fb purchase I've made - have been spreading the word as these are truely that good!!
OMG these have been the answer to my prayers - my young daughter was constantly leaking over the sides of other period underwear and as she is also on the autism spectrum was really hard to manage. The absorbency down the leg has changed both her and her carers lives.. Thank you, thank you, thank you...
Thank you Knicked for saving the day - saw a ad for these and have now purchased another 3 pairs. Always found all brands to have too slim of a strip of absorbency so would leak over the sides, well thats now a thing of the past as these are AMAZING, the wider absorbency which runs down the inside leg is genius (and unnoticeable)