Product supply timeline and titration schedule
| Week(s) | Supply | Dose | Capsules |
| 1 | First | 1 mg/day | 1 mg capsule |
| 2 | First | 2 mg/day | Two 1 mg capsule |
| 3 | First | 3 mg/day | Three 1 mg capsules |
| 4–6 | First | 4.5 mg/day | Three 1 mg capsules, plus one 1.5 mg capsule |
| 7–16 | Second | 4.5 mg/day* | One 4.5 mg capsule* |
There will be two dispensing time points when participants will be supplied with the study product. The first supply will be for weeks 1–6 and the second supply will be for weeks 7–16 of the study. For the first supply, participants will receive 1 mg and 1.5 mg capsules of the study product (low-dose naltrexone or placebo). They will be asked to up-titrate the dosage as tolerated and keep a diary of their dosage. In the second dispensing period, they will be supplied with capsules of their maximum tolerated dose.
*Or maximum tolerated dosage (ie, one 1 mg capsule, one 2 mg capsule or one 3 mg capsule).