GLP-3 retatrutide explained: triple-agonist mechanism, Phase 3 TRIUMPH data, dysesthesia signal, FDA timeline, and how PlexusDx’s currently-available compounded semaglutide and tirzepatide protocols compare to the pipeline asset.

The standard FDA tirzepatide dosing schedule moves through six weekly dose levels: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg, and 15mg, with at least four weeks between steps. This guide walks the week-by-week ladder for both injection and oral compounded tirzepatide, the milligram-to-unit conversions for compounded vials, missed-dose rules, and how the GIPR rs1800437 genetic variant can inform titration pace before week one.

Retatrutide (Lilly's investigational triple agonist) and orforglipron (Lilly's oral non-peptide GLP-1) are the two big pipeline stories in 2026 — but neither is FDA-approved yet. Here's the realistic timeline, the Phase 3 data, the announced and unknown pricing, and how PlexusDx's currently-available compounded semaglutide and tirzepatide protocols ($129–$509/mo) compare for someone who needs an option today rather than in 2028.

Foundayo's $149 headline is a one-month starter price — the real cash-pay year runs $3,338–$3,738 once you escalate. Compare PlexusDx Microdose GLP-1 ($129/mo flat), Semaglutide Oral ($209+/mo), and Tirzepatide Oral ($229+/mo) on annualized cost.

Foundayo costs $25/month with covered commercial insurance, $50/month on the Medicare GLP-1 Bridge, or $149–$349/month self-pay through LillyDirect. Most commercial plans don't cover GLP-1s for weight loss in 2026. Compare cash-pay PlexusDx Weight Management Protocols — Microdose at $129/mo flat, Semaglutide Injection $179–$229/mo, Tirzepatide Injection $229–$309/mo — with no membership fee.