SR-17 Cross-Taper Calculator

Day-by-day schedule for the SR-17 cross-taper protocol: preload, 7-OH cross-taper, hold, then SR taper down to a jump-off. Configurable per phase.

Your settings save automatically and reload next time you visit.

Stacked opioid exposure during preload and cross-taper.

During the preload and the cross-taper, you'll be on 7-OH (or MGM-15, MIT-A, pseudo) AND SR-17 at the same time. Keep naloxone (Narcan) on hand. Don't combine with alcohol, benzodiazepines, or other depressants. See the SR-17 page for full pharmacology and sourcing notes.

Your current 7-OH (or kratom synthetic)
Current total daily: 45 mg

The SR protocol is the same shape for 7-OH, MGM-15, MIT-A, and pseudo. If you're on the synthetics (MGM-15 / MIT-A / pseudo) or stacking multiple compounds, extend the preload — these run longer in the body and the 1-day preload is calibrated for pure 7-OH.

Phase 0 · Allergy test

Skip only if you've previously tested SR-17 from the same source and batch.

Phase 1 · Preload (SR ramps up, 7-OH unchanged)
Preload daily SR: 150 mg (50 × 3, every 8 h)

The community standard is 50 mg × 3 (every 6–8 h) for pure 7-OH. Some readers run higher per-dose totals early if 50 mg × 3 isn't holding them — raise SR, don't reach back for 7-OH.

Phase 2 · 7-OH cross-taper (7-OH drops to zero; SR holds)
Phase 3 · Hold (SR only, 7-OH already stopped)

Standard: 4 days at the preload total.

Phase 4 · SR taper down

Final SR dose before stopping completely. Standard: 25 mg.

Total duration
15 days
Total SR-17
1610 mg
Protocol
SR-17 cross-taper

Day-by-day schedule

DayPhaseSR-177-OHNotes
0Allergy test10 mg × 115 mg × 3 = 45 mg/dayTake ~10 mg SR-17, wait several hours, watch for any reaction. 7-OH (or whatever synthetic you're on) stays at your normal dose.
1Preload150 mg/day · 3 doses (~50 mg each)15 mg × 3 = 45 mg/dayStart SR-17 at full preload (50 mg every 6–8 h). 7-OH stays at the same dose.
2Preload150 mg/day · 3 doses (~50 mg each)15 mg × 3 = 45 mg/day
3Preload150 mg/day · 3 doses (~50 mg each)15 mg × 3 = 45 mg/day
4Cross-taper150 mg/day · 3 doses (~50 mg each)8 mg × 3 = 23 mg/dayCut 7-OH to 23 mg/day.
5Cross-taper150 mg/day · 3 doses (~50 mg each)Stop 7-OH. SR-17 carries you from here.
6Hold150 mg/day · 3 doses (~50 mg each)SR-17 only. Stable dose until the SR taper begins.
7Hold150 mg/day · 3 doses (~50 mg each)
8Hold150 mg/day · 3 doses (~50 mg each)
9Hold150 mg/day · 3 doses (~50 mg each)
10SR taper100 mg/day · 2 doses (~50 mg each)
11SR taper75 mg/day · 2 doses (~38 mg each)
12SR taper50 mg × 1
13Jump-off25 mg × 1Final SR-17 dose: 25 mg × 1. Stop after this dose.
14StopTaper complete.

The 7-OH doses on cross-taper days use the same per-day frequency you entered above.

"Copy schedule" puts the day-by-day plan on your clipboard as plain text. "Copy AI prompt" wraps it in scaffolding for an LLM to refine. "Save as PDF" opens a printable view in a new window.

SR-17 has never been studied in humans. All efficacy and safety data is rodent. The community protocol below is documented in detail on the SR-17 page; this calculator just does the day-by-day math from your inputs. SR-17 is still a mu-opioid agonist, it produces its own dependence and withdrawal, and the sourcing realities are real. Read the full page before committing to the protocol.

What this calculator builds

The SR-17 protocol is a cross-taper, not a single-substance taper. The calculator generates four sequential phases plus an optional allergy-test day:

  1. Phase 0 · Allergy test (~10 mg SR-17, wait several hours).
  2. Phase 1 · Preload. SR-17 ramps to full dose while 7-OH (or MGM-15 / MIT-A / pseudo) stays unchanged.
  3. Phase 2 · 7-OH cross-taper. 7-OH drops to zero — standard is cut-in-half then stop (2 days), custom is N equal cuts.
  4. Phase 3 · Hold. SR-17 only, at the preload total.
  5. Phase 4 · SR-17 taper down. SR steps down to your jump-off, then stop.

Defaults: a 3-day preload at 50 mg × 3 = 150 mg/day, standard cross-taper, 4-day hold, standard step-down (100 → 75 → 50 → 25 → jump). The SR-17 page documents the protocol with a 1-day preload as the textbook version; the calculator defaults to 3 days because most readers coming through here are on synthetics or stacks where the longer runway tends to work better. Drop it back to 1 for pure short-acting 7-OH, raise it further for harder cases.

When to extend the preload further

The 3-day default is the calculator’s middle-ground choice. Push it higher (4–5 days) if you’re stacking multiple compounds, coming off a high-dose pseudoindoxyl habit, or have a history of rough transitions where SR didn’t have enough time to settle before the 7-OH cuts started. Drop it back to 1 day if you’re on pure short-acting 7-OH and want the textbook-fast version on the SR-17 page.

What the calculator doesn’t do

  • It doesn’t source SR-17 for you. The SR-17 page covers what to look for and avoid.
  • It doesn’t decide whether SR-17 is the right path. Suboxone is the other community-validated path off the synthetics; the trade-offs are different.
  • It doesn’t model interactions with alcohol, benzodiazepines, or other depressants. Don’t combine. Keep naloxone (Narcan) on hand throughout.
  • It doesn’t replace community sense-checking. Bring your plan to the Discord before committing.

See also

Last updated: View source on GitHub