# N-of-1 Trial Protocol Template

> **License:** CC BY 4.0 — free to use and adapt with attribution to SingleArm (https://singlearm.com/guides/n-of-1-trials).
> **How to use:** Fill in every `{{placeholder}}` before you start tracking. Do not edit this document after the trial begins — start a new version instead.

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## 1. Trial identity

- **Participant identifier (private):** {{initials or pseudonym}}
- **Trial title:** {{short description, e.g. "Magnesium glycinate → sleep score"}}
- **Trial start date:** {{YYYY-MM-DD}}
- **Timezone used for logging:** {{IANA timezone, e.g. America/New_York}}
- **Version:** 1.0

## 2. Question

State the trial as a single question:

> Does **{{intervention}}** change **{{primary outcome}}** for me over **{{total trial length in weeks}}**?

## 3. Intervention

| Field | Value |
| --- | --- |
| Name | {{intervention name}} |
| Form / brand | {{capsule, powder, food, behavior, etc.}} |
| Dose or amount | {{exact dose}} |
| Timing | {{time of day, before/after food, etc.}} |
| Frequency | {{daily, 5 days on 2 off, etc.}} |
| Duration | {{weeks in intervention phase}} |
| Known risks | {{list, or "none known"}} |
| Clinician involved? | {{yes/no; if prescription, must be yes}} |

## 4. Outcomes (1–3 max)

| # | Outcome | Unit / scale | How I'll measure it | Time to log |
| --- | --- | --- | --- | --- |
| 1 | {{primary outcome}} | {{e.g. 0–100 sleep score}} | {{device or method}} | <60s |
| 2 | {{secondary, optional}} | | | |
| 3 | {{secondary, optional}} | | | |

## 5. Confounders to log alongside

- Sleep duration / quality
- Perceived stress (1–10)
- Alcohol (yes/no, servings)
- Illness / symptoms
- Travel / timezone change
- Other new supplements or medications
- Menstrual cycle day (if applicable)
- {{anything else specific to this trial}}

## 6. Phase plan

| Phase | Start date | End date | What I do |
| --- | --- | --- | --- |
| Baseline | {{YYYY-MM-DD}} | {{YYYY-MM-DD}} | Track outcomes only. No change. |
| Intervention | {{YYYY-MM-DD}} | {{YYYY-MM-DD}} | Add intervention. Keep tracking. |
| Washout (optional) | {{YYYY-MM-DD}} | {{YYYY-MM-DD}} | Stop intervention. Keep tracking. |
| Re-intervention (optional) | {{YYYY-MM-DD}} | {{YYYY-MM-DD}} | Add intervention again. Keep tracking. |

**Minimum phase lengths recommended:**
- Baseline ≥ 14 days
- Intervention ≥ 28 days for fast-moving outcomes, ≥ 56 days for slow-moving outcomes

## 7. Pre-committed success criteria

Before I start, I define what "worked" means numerically. I will not change this after seeing the data.

> The intervention will be considered to have moved my {{primary outcome}} for me if the intervention-phase mean differs from the baseline-phase mean by at least **{{X units}}** AND the pattern reverses during washout (if used).

## 8. Analysis plan

At the end of the trial I will compute, for each outcome:

- Mean and standard deviation per phase
- A simple line chart across all phases
- A note of confounders that were unusually high or low during each phase

## 9. Stop rules

I will pause or stop the trial early if any of the following occur:

- Any adverse effect I would not want to continue.
- New medication or diagnosis that changes the picture.
- Missed logs on more than {{N}} days in a two-week window (data becomes unreliable).
- Anything my clinician advises.

## 10. Ethical acknowledgement

I understand that this is an **educational, observational, personal experiment**. It is not clinical evidence. It cannot be generalized to anyone else. I will consult a qualified clinician before making any medical decisions based on what I observe.

Signed: {{name or initials}}
Date: {{YYYY-MM-DD}}

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## 11. Trial log (fill in daily)

| Date | Phase | Outcome 1 | Outcome 2 | Outcome 3 | Confounders / notes |
| --- | --- | --- | --- | --- | --- |
| {{YYYY-MM-DD}} | Baseline | | | | |
| {{YYYY-MM-DD}} | Baseline | | | | |
| … | … | | | | |

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## Attribution

Adapted from the N-of-1 methodology at https://singlearm.com/guides/n-of-1-trials — CC BY 4.0.