Where science meets nature.

Nuestra ciencia

Khapregesic® is a world first. It's a clinically tested, plant-based solution specifically designed for menstrual challenges.

Hey Sister! is disrupting the global pain market with Khapregesic®, our breakthrough active ingredient made from Australian-grown Khaya senegalensis.

Backed by over a decade of research and development, and created in collaboration with leading scientists, Khapregesic® is a clinically tested solution for period pain, PMS, mood swings, bloating and more.

Literally built from the ground up, from cultivating long-lost medicinal trees to conducting gold-standard clinical trials, this represents a new era in menstrual wellness.

Game-changing period pain, PMS, perimenopause and menopause relief.

Independent clinical trial evidence, backed by centuries of documented traditional medicine efficacy and a decade of Australian research, Hey Sister! proudly introduces the world’s first plant-based, clinically-tested solution for menstrual pain, PMS and menopausal symptoms.

Designed to support every stage of a woman’s menstrual journey - from your first period and PMS to perimenopause and menopause - Hey Sister! is here to empower you to live your fullest life.

Discover Relief

The single ingredient that packs a powerful punch.

High polyphenols (Antioxidants)

These are natural compounds that help keep cells healthy by dealing with things called “free radicals.”

Anti-Inflammatory

Affects body processes linked to swelling and irritation.

Prebiotic (Polysaccharides)

A type of fibre that feeds the good bacteria living in your gut.

Depurative (Blood Purifier)

Traditionally used to support how the body clears out waste and stays clean inside.

Bioavailable

This ingredient is easily taken in by the body, so it can start working quickly.

Analgesic (Pain Relief)

Linked to the body’s systems that deal with pain signals.

Our Commitment to Clinical Testing

The Hey Sister! key ingredient, Khapregesic®, has undergone comprehensive clinical testing with five clinical studies conducted to date⁵ inclusive of our most recent Gold-Standard Clinical Trial. Our ongoing commitment and investment into rigorous clinical research underscores the Hey Sister! ethos of efficacy and safety in addressing period pain and related physical and psychological symptoms of menstrual health.

Hey Sister! continues to revolutionise menstrual health by providing natural relief across all stages, including period pain, PMS, perimenopause, menopause, and post-menopausal symptoms.

View Clinical Results Summary

View the full clinical trial publication on PubMed here.

5. Five Clinical Studies conducted to date: An unpublished, open-label Safety Study (Jun2015 Title: Adult Human sub-chronic screening study for Khapregesic® (Dry Bark 20g daily (x7))), an unpublished, open-label investigation into Clinical-Efficacy (Jan2019 Title: Abdominal Pain from menstruation, IBS &/or Anxiety. A Khapregesic® sub-chronic dose study.), a Gold-Standard Clinical Trial, (Jan2025 Title: An examination into the safety and efficacy of Khapregesic® , a Khaya senegalensis preparation, on pain, physical and emotional wellbeing in women experiencing menstrual distress: a randomised, double-blind, placebo-controlled trial.) and two unpublished, open-label observational studies focusing on senior adults, split into two distinct groups: females and males, ( Jan2025, Title: A Chronic duration Elevated Dose Study of Khapregesic® on safety and efficacy on Older Females.) ( Jan2025, Title: A Chronic duration Elevated Dose Study of Khapregesic® on safety and efficacy on Older Males.)
How it works:

The Natural Power of Khapregesic®

True disruption occurs when multiple disciplines collide, creating something new and outstanding. At Hey Sister!, our commitment to rethinking pain relief and menstrual distress led to a groundbreaking discovery: Khapregesic®, a plant-based medicine derived from the Khaya senegalensis tree.

Our journey began with the vision to create a revolutionary product for women and AFAB health. After more than 10 years of rigorous research into plant science, medicine, and process engineering, we didn’t just stop at the laboratory. We pushed further – through regulatory approvals, clinical trials⁵, and real-world use – to bring natural relief to millions of women every day.

True disruption occurs when multiple disciplines collide, creating something new and outstanding. At Hey Sister!, our commitment to rethinking pain relief and menstrual distress led to a groundbreaking discovery: Khapregesic®, a plant-based medicine derived from the Khaya senegalensis tree.

Our journey began with the vision to create a revolutionary product for women and AFAB health. After more than 10 years of rigorous research into plant science, medicine, and process engineering, we didn’t just stop at the laboratory. We pushed further – through regulatory approvals, clinical trials⁵, and real-world use – to bring natural relief to millions of women every day.

5. Five Clinical Studies conducted to date: An unpublished, open-label Safety Study (Jun2015 Title: Adult Human sub-chronic screening study for Khapregesic® (Dry Bark 20g daily (x7))), an unpublished, open-label investigation into Clinical-Efficacy (Jan2019 Title: Abdominal Pain from menstruation, IBS &/or Anxiety. A Khapregesic® sub-chronic dose study.), a Gold-Standard Clinical Trial, (Jan2025 Title: An examination into the safety and efficacy of Khapregesic®, a Khaya senegalensis preparation, on pain, physical and emotional wellbeing in women experiencing menstrual distress: a randomised, double-blind, placebo-controlled trial.) and two unpublished, open-label observational studies focusing on senior adults, split into two distinct groups: females and males, (Jan2025, Title: A Chronic duration Elevated Dose Study of Khapregesic® on safety and efficacy on Older Females.) (Jan2025, Title: A Chronic duration Elevated Dose Study of Khapregesic® on safety and efficacy on Older Males.)

Strong Plant-Based Pain Relief and Anti-Inflammatory Action1

Uniquely targets multiple pain markers by engaging antinociceptive activity, stimulating opioid receptors and suppressing prostaglandin E2 production, effectively reducing inflammation and delivering natural relief.

Strong Plant-Based Pain Relief and Anti-Inflammatory Action1

Uniquely targets multiple pain markers by engaging antinociceptive activity, stimulating opioid receptors and suppressing prostaglandin E2 production, effectively reducing inflammation and delivering natural relief.

1. A1) Kolawole, O.T., M.O. Akiibinu, and E.O. Awe, Evaluation of Anti-inflammatory and Antinociceptive Potentials of Khaya senegalensis A. Juss (Meliaceae) Stem Bark Aqueous Extract.
Journal of Advances in Medicine and Medical Research, 2013. 3(2): p. 216-229. A2) Androulakis, X.M., et al., Chemopreventive effects of Khaya senegalensis bark extract on human colorectal cancer. Anticancer Res, 2006. 26(3B): p. 2397-405. A3) Lompo, M., Mechanism of the Anti-inflammatory Activity of Khaya senegalensis A. Juss. (Meliaceae). International Journal of Pharmacology, 2007. 3(2): p. 137-142. A4) Ukekpe, U.S., et al., Phytochemical Screening and Antioxidant properties of Stem bark of Khaya senegalensis (Dry- zone Mahogany). J. Chem Soc. Nigeria, 2019. 44(7): p. 1268-1272.

B1) Zhou, M.M., et al., Anti-inflammatory activity of Khayandirobilide A from Khaya senegalensis via NFkappaB, AP-1 and p38 MAPK/Nrf2/HO-1 signaling pathways in lipopolysaccharide-stimulated RAW 264.7 and BV-2 cells. Phytomedicine, 2018. 42: p. 152-163. B2) Ukekpe, U.S., et al., Phytochemical Screening and Antioxidant properties of Stem bark of Khaya senegalensis (Dry- zone Mahogany). J. Chem Soc. Nigeria, 2019. 44(7): p. 1268-1272. B3) Shin, J., H.Y. Song, and M. Lee, Sudachinoid- and Ichangensin-Type Limonoids from Citrus junos Downregulate Pro-Inflammatory Cytokines. Int J Mol Sci, 2020. 21(18). B4) Kandeda, A.K., et al., An aqueous extract of Khaya senegalensis (Desv.) A. Juss. (Meliaceae) prevents seizures and reduces anxiety in kainate-treated rats: modulation of GABA neurotransmission, oxidative stress, and neuronal loss in the hippocampus. Heliyon, 2022. 8(5): p. e09549.

High Polyphenol, Limonoid and Antioxidant Levels2

Plant-derived polyphenols in Khapregesic® protect and repair cells by combating oxidative stress. These compounds play a critical role in reducing free radical damage and supporting overall cellular health. Khapregesic® is also rich in limonoids.

In a recent animal trial, “KS reduced anxiety, likely through its effects on GABA neurotransmission (a neurotransmitter implicated in anxiety), and neuroprotective effects”.

High Polyphenol, Limonoid and Antioxidant Levels2

Plant-derived polyphenols in Khapregesic® protect and repair cells by combating oxidative stress. These compounds play a critical role in reducing free radical damage and supporting overall cellular health. Khapregesic® is also rich in limonoids.

In a recent animal trial, “KS reduced anxiety, likely through its effects on GABA neurotransmission (a neurotransmitter implicated in anxiety), and neuroprotective effects”.

2. B1) Zhou, M.M., et al., Anti-inflammatory activity of Khayandirobilide A from Khaya senegalensis via NFkappaB, AP-1 and p38 MAPK/Nrf2/HO-1 signaling pathways in lipopolysaccharide-stimulated RAW 264.7 and BV-2 cells. Phytomedicine, 2018. 42: p. 152-163. B2) Ukekpe, U.S., et al., Phytochemical Screening and Antioxidant properties of Stem bark of Khaya senegalensis
(Dry- zone Mahogany). J. Chem Soc. Nigeria, 2019. 44(7): p. 1268-1272. B3) Shin, J., H.Y. Song, and M. Lee, Sudachinoid- and Ichangensin-Type Limonoids from Citrus junos Downregulate Pro-Inflammatory Cytokines. Int J Mol Sci, 2020. 21(18). B4) Kandeda, A.K., et al., An aqueous extract of Khaya senegalensis (Desv.) A. Juss. (Meliaceae) prevents seizures and reduces anxiety in kainate-treated rats: modulation of GABA neurotransmission, oxidative stress, and neuronal loss in the hippocampus. Heliyon, 2022. 8(5): p. e09549.

Naturally Occurring Prebiotics3

The polysaccharides in Khapregesic® support gut health, helping you feel your best during your cycle and beyond.

Naturally Occurring Prebiotics3

The polysaccharides in Khapregesic® support gut health, helping you feel your best during your cycle and beyond.

3. Liu,X., et al, Research advance about plant polysaccharide prebiotics, benefit for probiotics on gut homeostasis modulation. Food Bioscience Volume 59, June 2024, 103831

What sets Khapregesic® apart?

  • Built on expertise
    The majority of our scientific team over the years has been female, driven by a personal mission to innovate and transform the treatment of menstrual challenges into a simple more naturally derived process.
  • Collaboration with the best
    From exploring plant genetics in-house to groundwater interactions within our plantation with leading experts at CSIRO. Our discovery into medicines has seen collaborations with many Australian Universities and private research organisations culminating with the most recent independent Gold-Standard Clinical Trial² conducted by Dr Adrian Lopresti at CRA³.
  • Commitment to sustainability
    Using patent-pending harvest technology, we ensure that our medicinal trees thrive post-harvest, creating a renewable natural resource while storing carbon to benefit the planet
  • Advanced phyto-medicinal research
    Our team of bio-chemists, specialists in phytochemistry, identified medicinal properties and active compounds, creating a whole natural medicine (not an extract) backed by a trifecta of traditional medicine, modern science techniques and clinical testing.
  • Certified clean for elite athletes:
    We understand the importance of trust and transparency, especially for athletes who rely on clean, performance-safe products. That’s why all Hey Sister! products have been lab tested at 'Human and Supplement Testing Australia' (HASTA) tested and passed. Our flagship OG PERIOD product has gone one step further and been HASTA-certified⁴ and entered on to the Australian Government's Sport Integrity App.
  • Batch Tested
    Hey Sister! is now on the prestigious sporting codes choice for clean products, the Batch Tested website. Batch Tested is the only specialist provider for all professional athletes and sporting codes, ensuring all products are free from over 200 substances banned by the World Anti-Doping Agency (WADA). This means elite athletes can use Hey Sister! products with total confidence — without compromising their integrity, performance, or compliance with antidoping regulations.

2. Gold-Standard Clinical Trial - Ethics approved, randomised, double-blind, placebo-controlled clinical trial
3. CRA - Clinical Research Australia
4. HASTA independent testing and verification studies (B2703 & B2703A, Aug 2028, RS23/17294)

Why Period Pain Isn’t Normal

Period pain is often dismissed as “normal,” but it’s actually a physiological response to elevated levels of prostaglandins. These hormone-like substances are released during menstruation to help the uterus contract and shed its lining. However, excessive prostaglandin levels can overstimulate uterine contractions, leading to cramping and discomfort.

What are Prostaglandins?
And what is their role in menstrual pain?

Prostaglandins are lipid compounds derived from fatty acids. They are part of a group of molecules called eicosanoids.

How They Function:
Unlike traditional hormones (e.g., oestrogen, insulin etc) that are produced by specific glands and travel through the bloodstream to distant sites, prostaglandins are produced at the site of tissue damage or other localised events. They act locally, mediating processes such as inflammation, pain, and uterine contractions.

Role in Menstrual Pain:
During menstruation, prostaglandins are released to help the uterus contract and shed its lining. However, when prostaglandin levels are too high, they can cause excessive contractions, resulting in cramping, inflammation, and discomfort.

The Role of COX-2 in Prostaglandin Production

Cyclooxygenase-2 (COX-2) is an enzyme that plays a crucial role in the production of prostaglandins. Here’s how it works:

Triggering Prostaglandin Production
When tissue is damaged, inflamed, or stimulated (e.g. during menstruation), the body activates COX-2. This enzyme converts a fatty acid called arachidonic acid — found in cell membranes — into prostaglandin precursors.

Prostaglandins and Uterine Contractions
During menstruation, COX-2 activity in the uterus leads to the release of prostaglandins. These prostaglandins help the uterus contract to shed its lining.

  • Normal Levels: Aid in the natural process of menstruation.
  • Excessive Levels: Cause over-contraction of the uterine muscles, leading to cramping, inflammation, and pain.


Why Excess Prostaglandins Cause Pain
Excessive prostaglandins overstimulate pain receptors in the uterine area. This is why menstrual cramps (dysmenorrhea) are often associated with heightened COX-2 activity.

How COX-2 Inhibitors Work
COX-2 inhibitors block the activity of the COX-2 enzyme, reducing prostaglandin production.

  • Result: Fewer prostaglandins mean less inflammation and pain without completely halting the natural processes of the body.

The information provided above is for educational purposes only and is not intended to describe or imply the action of any therapeutic product. It should not be interpreted as medical advice. For personal health concerns, please consult a healthcare professional.

Cleveland Clinic - Prostaglandins: What It Is, Function & Side Effects

L S Simon - Role and regulation of cyclooxygenase-2 during inflammation

How Hey Sister! Helps

Khapregesic®, the key ingredient in Hey Sister! products, has been traditionally used and clinically studied for its role in supporting menstrual wellbeing. Our formulation is developed to help reduce abdominal cramping and maintain comfort during your period.

The Science Timeline

From Tree to Tablet: A Decade of Research

Every tablet of Hey Sister! is the result of years of innovation, collaboration, and dedication.

OUR JOURNEY AT A GLANCE:

2010

CSIRO research on groundwater interaction with our Khaya trees

2013

Safe medicinal plantation established. Soil & tree component testing completed, first annual Certified Organic audit conducted & passed

2013-2018

Advanced harvest technology, sustainable farming and water practices developed.

2015

Southern Cross University - HPLC-MS constituent profile and ID of micro and macro characteristics

2016

UWA Marshall Centre research to determine a safety profile of key gut microbiota

2017

Griffith University - purification and structural characterisation of bioactive compounds

Eurofins CRO - Genetic DNA test (AMES) and clinical safety study conducted

2017 - 2022

Regulatory dossier prep and approval granted for Khaya senegalensis

2018

Advanced processing technology prototype developed to create Khapregesic®

2023

Successful market trial of Khapregesic®

2024

The Hey Sister! online launch is a success with Urban List

Pharmacy rollout nationwide commences

Two observational clinical studies conducted in over 50's of both sexes

2025

The 1st randomised, double-blind placebo-controlled Clinical Trial conducted & is an unprecedented success

Over 600 pharmacies stock Hey Sister! by April

Today

Empowering women worldwide with
science-backed, natural relief

Tested by Research, Backed by Tradition

Hey Sister! is the first period pain relief product to combine traditional medicine practices with cutting-edge science. Our commitment to rigorous testing and regulatory compliance ensures you’re getting a product that’s both effective and safe.