The DoNotAge SureSleep study is useful precisely because it is not the same kind of evidence as a randomized clinical trial. In May 2026, DoNotAge published a 21-day prospective real-world customer study in which 51 analysed customers logged 1,472 daily check-ins while using the finished SureSleep® product in ordinary life.
The signals were large for sleep quality and next-day energy. But the study had no placebo arm, no randomization and no blinding, so it cannot separate the effect of SureSleep from expectation, natural variation, regression to the mean or other behavioral changes that occur when people start tracking their sleep.
SureSleep study at a glance
| Study feature | Published detail |
|---|---|
| Design | Prospective, observational, single-arm real-world customer cohort |
| Duration | 21 days |
| Confirmed participants | 60 |
| Analysed completers | 51 |
| Countries | 13 |
| Daily check-ins | 1,472 |
| Population | Existing DoNotAge customers looking for better sleep |
| Control | Within-subject baseline; each participant served as his or her own comparison |
| Endpoint | Final five study days versus pre-product baseline |
| Outcomes | Sleep quality, daytime energy, sleep onset and night waking |
| Randomization / placebo / blinding | None |
| Study operator | BioStackr, commissioned by DoNotAge.org, according to the published study page |
What did the 51 analysed customers report?
| Outcome | Published result | Reported effect size |
|---|---|---|
| Sleep quality | 88% improved; average 5.15 → 6.77/10 (+31%) | Cohen’s d=1.13 |
| Daytime energy | 94% improved; average 5.06 → 6.65/10 (+31%) | Cohen’s d=1.22 |
| Sleep onset | 76% moved toward easier sleep onset | Cohen’s d=0.88 |
| Night waking | 53% reported fewer night wakes | Cohen’s d=0.36 |
The study page also reports that 55% of participants felt a benefit within the first week, 70% rated SureSleep among the best sleep products they had used, 47% said it performed better than expected and 79% found it very easy to fit into their routine.
Those latter figures are useful for understanding customer experience and adherence. They are not clinical endpoints and should not be treated as substitutes for placebo-controlled efficacy data.
How was the baseline comparison done?
Participants completed a pre-product baseline window before the intervention arrived. The published methods describe a four-to-five-day baseline and compare that period with the final five days of the study.
Every day, participants rated sleep quality and daytime energy on 10-point scales, reported how easily they fell asleep and logged night waking. Because the same people supplied baseline and treatment-period data, each participant acted as his or her own control.
This within-person design is more informative than simply asking customers at the end whether they “liked” the product, because it produces repeated before-and-after measurements. It still lacks the placebo group needed to estimate how much of the change is specifically attributable to SureSleep.
How did the study handle real-life disruptions?
The real-world design deliberately tracked common confounders including alcohol, travel, illness, intense exercise and unusual stress. The study page says those tagged days were excluded from the primary analysis and reviewed separately as context.
The published analysis used Cohen’s d effect sizes, 95% confidence intervals and 10,000-iteration bootstrap resampling. That is a more structured analytical approach than a simple collection of testimonials, although statistical sophistication cannot replace the missing randomized placebo group.
Who designed and analysed the study?
According to DoNotAge’s published study page, the project was commissioned by DoNotAge.org and conducted by BioStackr. The page states that BioStackr designed the protocol, managed data collection, set the confound-exclusion rules and ran the analysis.
DoNotAge says it did not have access to the raw participant submissions and did not control the metrics, exclusion rules or results. The page also states that BioStackr receives no commission, affiliate fee or revenue from SureSleep sales.
BioStackr’s role should therefore be described as reported on the company-hosted page, not equated with an independently funded academic trial.
What does the study do well?
- Finished-product relevance: participants used SureSleep®, not isolated ingredients.
- Repeated daily measurement: 1,472 check-ins provide substantially more information than a one-time post-purchase survey.
- Baseline before intervention: participants supplied data before taking the product.
- Real-world conditions: travel, alcohol, stress, exercise and other disruptions were recorded rather than pretending every night occurred under laboratory conditions.
- Transparent limitations: the source page itself explicitly says the study had no placebo, randomization or blinding and does not present it as a clinical efficacy trial.
What can’t the study prove?
It cannot isolate a placebo-adjusted SureSleep effect
Without a placebo group, participants knew they were taking a sleep product. Expectation alone can influence subjective sleep ratings, especially in a cohort actively seeking better sleep.
It cannot rule out regression to the mean
People often start an intervention when a problem is particularly noticeable. Some improvement may occur naturally even without treatment.
The main outcomes were self reported
The study did not use polysomnography, actigraphy or another objective sleep endpoint as its primary measurement. The reported changes describe participant experience, which is valuable, but different from objectively measured sleep architecture.
The sample came from existing DoNotAge customers
Participants were already DoNotAge customers across 13 countries, and many had previously tried sleep products. That population may not represent a general community sample or people with clinically diagnosed sleep disorders.
There was no random assignment
Everyone received SureSleep. The design therefore cannot create the balanced comparison groups that randomization provides.
What does this mean for SureSleep?
The strongest defensible conclusion is that a 21-day real-world cohort of existing DoNotAge customers reported substantial improvements in sleep quality and next-day energy while using SureSleep, with smaller improvements in sleep onset and night waking.
That is meaningful real-world finished-product evidence. It is not proof that SureSleep caused the entire change, and it should not be described as randomized clinical efficacy evidence.
The natural next step would be a larger randomized, double-blind, placebo-controlled SureSleep trial using validated sleep questionnaires and objective measurements such as actigraphy alongside daily participant-reported outcomes.
How this study differs from DoNotAge Clinical Trials 1 and 2
- Clinical Trial 1 randomized participants to the DoNotAge® daily formula or placebo and measured well-being and fatigue over 60 days.
- Clinical Trial 2 randomized participants to the daily formula or placebo and measured whole-blood NAD+ over 28 days.
- The SureSleep study followed customers using the sleep product in real life with no placebo arm.
Keeping those designs separate makes the overall DoNotAge evidence portfolio easier to evaluate without flattening every study into the same evidentiary category.
Primary source
DoNotAge SureSleep study FAQ
How many people were in the SureSleep study?
Sixty customers were confirmed and 51 met the criteria for the analysed cohort.
How long did the study last?
Twenty-one days, with 1,472 daily check-ins reported across the study.
Was the SureSleep study placebo controlled?
No. It was a prospective observational single-arm cohort. Each participant was compared with his or her own pre-product baseline.
Was it randomized or blinded?
No. The source explicitly states that there was no randomization and no blinding.
What improved the most?
The strongest reported changes were sleep quality and daytime energy, both of which increased by roughly 31% on the study page’s cohort averages.
Does the study prove SureSleep works?
It shows that these customers reported improvement while using SureSleep under real-world conditions. Because there was no placebo arm, it cannot establish how much of that improvement was caused specifically by the product.
Who analysed the data?
The DoNotAge study page states that BioStackr designed the protocol, managed the data collection, set exclusion rules and performed the analysis, while DoNotAge commissioned the project.
Linked entities and research
DoNotAge SureSleep 21-Day Real-World Customer Study
DoNotAge.org commissioned the study in existing SureSleep customers. The company study page states that BioStackr designed the protocol, managed data collection, set exclusion rules and performed the analysis, with no commission or affiliate revenue from SureSleep sales.