What's keeping you awake — the upstream causes

What actually decides this outcome, in order of size

This pathway is the one place on the site where the two biggest levers are a referral and a behavioral program, and neither is a product. Ranked by how often each one is the actual answer:

1. Sleep-disordered breathing, and it is not rare. An estimated 936 million adults aged 30 to 69 have mild to severe obstructive sleep apnea worldwide, 425 million of them moderate to severe Benjafield 2019. It produces the exact presentation this pathway attracts, exhausted after 8 hours in bed, and there is no blood marker for it at any price. The test is a sleep study.
2. Conditioned insomnia, treated as a condition. Across 37 studies, CBT-I produced remission in 36.0% of patients against 16.9% of controls, a pooled odds ratio of 3.28 (95% CI 2.30 to 4.68, P<0.001), including in people whose insomnia was comorbid with another illness Wu 2015. That is the comparator every sedative on this page is up against.
3. Caffeine, later than you think. 400 mg taken 6 hours before bedtime measurably disrupts sleep Drake 2013. The half-life runs about 5 to 6 hours and is set by CYP1A2, whose activity varies several-fold between people and is slowed by oral contraceptives, so a 3pm coffee is a 25% blood level at midnight in a slow metabolizer.
4. Alcohol, which is the commonest self-prescribed sedative. It shortens sleep onset and then suppresses REM in the first half of the night, with a rebound and a sympathetic surge in the second. It is the single best explanation for a reliable 3am waking.
5. The endocrine causes this pathway is actually about. Thyrotoxicosis, a cortisol curve shifted late, perimenopausal progesterone withdrawal, iron deficiency driving restless legs, and nocturnal glucose swings. Each of these has a number attached, which is what makes them worth testing rather than guessing.
6. The compounds on this page. Real, and sixth.

The order to run these in, and what has to be true first

Screen, then behave, then test, then match a compound to what the test said. Reversing the last two is the reason a shelf of sedatives stops working after a fortnight.

1. Screen for apnea before anything else. Snoring, a witnessed pause, a collar over 17 inches, or a partner who has moved rooms is enough to justify a home sleep test Benjafield 2019. Every sedative on this page relaxes the same pharyngeal muscles whose collapse is the problem.
2. Fix the caffeine window and the alcohol before buying anything. A hard cut-off 8 hours before bed costs nothing and removes the commonest confounder from every measurement you take next Drake 2013.
3. Then test, and test for the cause rather than the symptom. TSH (Thyroid-Stimulating Hormone) with Free T4 (Thyroxine), because a suppressed TSH under 0.4 mIU/L with a high free T4 is thyrotoxic insomnia and no sedative fixes it; the TSH-free T4 relationship is log-linear, so a small TSH change reflects a large thyroid hormone change Razvi 2019. Cortisol (AM) drawn before 9am for the rhythm. Ferritin for restless legs, read beside hs-CRP (High-Sensitivity C-Reactive Protein) because ferritin is an acute-phase protein Luo 2023. Progesterone, Estradiol, Standard (ECLIA) and LH & FSH where the waking started in the forties. HbA1c (Hemoglobin A1c) with Fasting Insulin for the reproducible 3am wake with a racing heart.
4. Then match the compound to the finding. Phosphatidylserine, Ashwagandha, Magnolia Bark or Holy Basil (Tulsi) where the cortisol curve is the finding. Iron only where ferritin is under 75 ng/mL and the legs are the complaint. Berberine or Myo-Inositol where the glycemic markers are. Vitex (Chasteberry) or Perimenopause Support where the hormone panel is. Gut Repair (EnteroMend) where the waking tracks reflux rather than arousal.

What gets bought for this that cannot move it

Nothing on this page treats obstructive sleep apnea, and several things on it make apnea worse. Sedatives lower upper-airway muscle tone and raise the arousal threshold, which lengthens each event. With 425 million adults carrying moderate to severe disease Benjafield 2019, this is not an edge case on a page about unexplained waking. If every marker below is optimal and you snore, the purchase was the wrong one.

A sedative does not treat a maintenance problem. Anything acting through GABA-A shortens sleep onset; the reader on this pathway usually falls asleep fine and wakes at 3am. Onset agents belong on the GABAergic onset pathway and will read as a failure here.

Melatonin is a phase-shifting hormone, not a hypnotic. Its receptors are circadian, and taking 5 mg at midnight for a 3am waking asks a clock signal to do a sedative's job. That argument belongs on the circadian pathway.

And a supplement has never been compared with what actually works. CBT-I has 37 randomized trials and a remission odds ratio of 3.28 Wu 2015. Not one compound on this page has been tested against it. That is not an argument against the compounds; it is the reason the behavioral program goes first.

How you would know it was working, on a real read-out and a real timescale

Insomnia is the goal most vulnerable to a good week being mistaken for an effect, so every read-out here has a minimum window attached.

• A sleep diary for 14 nights before and 14 after, every time. Night-to-night variability in sleep-onset latency is large enough that a 3-night comparison is noise. This is the read-out that costs nothing and is skipped most often.
• TSH (Thyroid-Stimulating Hormone) and Free T4 (Thyroxine) at 6 to 8 weeks after any thyroid change. The pituitary integrates thyroid hormone over roughly 6 weeks, so a TSH drawn earlier reports where you were, not where you are Razvi 2019.
• Ferritin at 12 weeks, targeting over 75 ng/mL where restless legs is the complaint. Brain iron follows serum iron slowly and the symptomatic threshold sits well above the 15 ng/mL that defines anemia risk. Read it beside hs-CRP (High-Sensitivity C-Reactive Protein) or an inflamed value will look like success Luo 2023.
• Cortisol (AM) before 9am, on two separate mornings. Cortisol is pulsatile and a single draw catches a pulse or a trough. Two concordant mornings is a finding; one is a coin toss.
• HbA1c (Hemoglobin A1c) at 12 weeks with Fasting Insulin. The 120-day red-cell lifespan sets the floor on how soon glycated hemoglobin can mean anything, and insulin is the marker that moves first.

What will fool you. Any sedative improves the first 3 to 5 nights through expectancy alone, and alcohol on 2 nights of a 14-night diary is enough to hide a real improvement. So is a single night of under 6 hours before a morning cortisol draw, which raises the value.

Sources read for these sections

• Benjafield AV. Estimation of the global prevalence and burden of obstructive sleep apnoea: a literature-based analysis. Lancet Respiratory Medicine 2019;7(8):687-698 · PMID 31300334
• Wu JQ, et al. Cognitive Behavioral Therapy for Insomnia Comorbid With Psychiatric and Medical Conditions: A Meta-analysis. JAMA Internal Medicine 2015;175(9):1461-72 · PMID 26147487
• Drake C. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. Journal of Clinical Sleep Medicine 2013;9(11):1195-1200 · PMID 24235903
• Razvi S, et al. Challenges in Interpreting Thyroid Stimulating Hormone Results in the Diagnosis of Thyroid Dysfunction. Journal of Thyroid Research 2019 · PMID 31662841
• Luo H, et al. A Practical Guide to Adjust Micronutrient Biomarkers for Inflammation Using the BRINDA Method. Journal of Nutrition 2023 · PMID 36792034