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Switching from Mounjaro 12.5mg over to Reta

10 replies8 peopleOct 7, 2026☆ Follow
Summary

what starting dose of reta after stopping 12.5 mg mounjaro three weeks ago

Participants suggest beginning at 2 mg weekly for several weeks before any increase, noting that prior tirzepatide use may allow slightly faster titration for some. One person reported moving directly from 15 mg tirz to 8 mg reta without issue, while another described a friend tolerating 3 mg reta after high-dose tirz. Several emphasize that tirzepatide provides stronger appetite control than reta.

What this discussion establishesWhere people disagree

whether a 4-week titration interval is necessary for someone already exposed to tirzepatide or if 2-week steps are acceptable

Still open

how individual tolerance and heart-rate response to the glucagon component will affect final dosing

Nothing here is advice.

10 replies · 8 people
RustAlder52archiveopening post5d

i searched the forum and reddit but came up empty. my brothers dad used to take mounjaro at 12.5 mg until the cost became too much. he had solid weight loss on it but has been struggling since stopping. he wants to try the reta that i'm on. what starting amount makes sense for him?

PlainAnchor66archive5d

i came across this chart but don't know how reliable it is. i still wouldn't put someone straight onto a high dose without working up.

NorthWillow72archive5d
↳ replying to @RustAlder52 (opening post)

was he still taking it or already stopped? how long since the last shot?

PlainAlder11archive5d

have him begin at 2 mg of reta and stay there for four weeks. three weeks off should be sufficient for the previous drug to clear.

RustAlder52archive5d
↳ replying to @PlainAlder11

yeah that lines up with what i was thinking.

SlowAlder89archive5d

same view here. start him at 2 mg and wait at least three weeks before going up. make sure he knows tirzepatide usually suppresses appetite more effectively than reta does.

search for the word bridge plus my username to see how i moved from 5 mg zepbound over to reta back in january. i wouldn't drop straight from 12.5 mg down to 2 mg, though goals and tolerance differ for everyone.

SlowAlder89archive5d
↳ replying to @LevelThistle44

a friend of mine came off 15 mg tirzepatide after more than a year when insurance ended. he started reta at 3 mg weekly after roughly two months off. when he later added tirzepatide back alongside the reta he began at 6 mg and tolerated it fine, then moved to 9 mg the next week.

KeenPebble33archive4d
↳ replying to @RustAlder52 (opening post)

because he already has exposure to tirzepatide the glp-1 and gip effects are familiar, so hunger is the main issue returning. the new glucagon part will raise heart rate and there's no avoiding that. when i switched i went straight from 15 mg tirz to 8 mg reta with no problems. starting at 2 mg and adding 1 mg every two weeks to check hunger control should work fine. four-week steps seem unnecessary once someone has prior exposure.

GreyHarbour55archive4d

i've been in maintenance since may 2025. after a full year on tirzepatide i reached 15 mg for five months. i tapered to 10 mg, added a small amount of cagri, then stopped tirzepatide and began 1 mg reta with cagri. two weeks later i moved to 3 mg reta and later dropped the cagri. weight has stayed stable at 3 mg reta once a week and i can eat normally again.

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