Your midnight saliva collection
This test measures the two hormones that set your sleep–wake rhythm — melatonin and cortisol — from a single saliva sample taken at midnight. Collecting at the right time, in low light, is what makes your result meaningful.
A simple test you do at home
Your kit and instructions are posted directly to you — no collection centre visit needed. Collect one saliva sample at home at midnight, then mail it back to the lab in the prepaid packaging provided.
When to collect
You'll take one sample at midnight — and keeping the light low in the lead-up is essential.
Why collect in the dark?
Light — especially the blue light from phones, TVs and bright bulbs — suppresses melatonin within minutes. If you're exposed to bright light before or during collection, your result won't reflect your natural night-time levels. Keep the lights low through the evening, put screens away in the hour before, and collect in a dark or dimly-lit room. A low night-light is fine if you need to see. Try to collect while relaxed, before 2 am.
What this test measures
Measures: Melatonin · Cortisol (Midnight)
Before you collect
A little preparation in the evening keeps your result accurate.
Avoid this evening
Caffeine, alcohol and nicotine (smoking) all disrupt your sleep hormones — avoid them in the evening before you collect, unless your provider advises otherwise.
2 hours before
Do not eat, brush or floss your teeth, or use mouthwash (so, from around 10 pm). You may drink a little water during this time.
Just before
Wash your hands with soap and water, and rinse your mouth with water 15 minutes before collecting — keeping the lights low.
Taking melatonin or hormone products?
A melatonin supplement will directly raise your melatonin result — check with your practitioner whether to pause it before testing, and note it on your request form if you continue. Continue other medications as prescribed unless advised. If you use a hormone or steroid product (for example a cortisol/hydrocortisone cream), note it on your form and follow the timing below.
| Product type | When to collect your sample |
|---|---|
| Creams / gels / capsules | 12–24 hours after last dose |
| Troche / sublingual | 36 hours after last dose |
| Patches | 24–48 hours after applying patch |
| Injections / pellets | Midpoint between treatments |
Not sure about timing?
If you're unsure how to time your sample around a supplement or medication, contact the lab on info@i-screen.com.au before you begin, or check with your practitioner.
Collecting your sample
You'll collect one saliva sample at midnight. Take your time and fill the tube properly — an insufficient sample can't be processed.
- In a dark or dimly-lit room (screens and bright lights off — a low night-light is fine), wash your hands, rinse your mouth with water, and wait at least 15 minutes before collecting.
- Unscrew the lid of the collection tube and hold it to your lips.
- Tilt your head forward and let saliva pool naturally inside your mouth.
- Allow saliva to passively pool into the tube — don't force or spit. Continue until you reach the fill line with liquid saliva.
- Fill the tube to the line with liquid saliva. Avoid foam or bubbles — tap the tube with a fingernail or on a hard surface to settle them.
- During collection, don't cough, clear your throat, or draw mucous from the back of your throat into the tube.
- Screw the cap on tightly to avoid any leakage in transit.
- Label the tube straight away with the details below — the collection time is essential.
Label your tube with:
- Your first name and surname
- Your date of birth
- The time collected (including am or pm)
- The date of collection
Packing & sending
- Check your request form is complete — full name, date of birth, address and contact number. Details must match your tube label.
- Place your labelled tube into the sealable section of the specimen transport bag, and the request form into the non-sealable pocket.
- Seal everything inside the prepaid return envelope provided and post it via your nearest Australia Post outlet or express post box.