# What Once Weekly Treatments Reveal About Drug Delivery
The way we take medicine is changing. For decades, patients have swallowed pills every morning or given themselves daily injections. But a new generation of medications is challenging this routine. Once-weekly treatments are becoming reality, and they’re teaching us something important about how drugs move through our bodies and what patients actually need.
The shift toward weekly dosing started with a simple observation: people don’t like taking pills every day. Missing doses happens. Remembering to take medication at the right time, avoiding food interactions, and managing absorption problems creates friction in treatment. Weekly injections remove much of this burden. Instead of thirty daily doses, a patient gets one injection. The convenience alone changes behavior.
Consider levothyroxine, a hormone replacement therapy for hypothyroidism that patients have taken orally for generations. A new injectable version called XP-8121 is now in clinical trials, delivering the same hormone once weekly under the skin. The Phase 2 data shows something striking: the medication maintains stable thyroid hormone levels using about four times the daily oral dose. More importantly, 72 percent of trial participants preferred the weekly injection to daily pills. Treatment satisfaction scores for effectiveness, convenience, and overall satisfaction were higher with the injection than with traditional oral therapy.
This preference isn’t just about convenience. Patients report reduced anxiety about managing their condition. They no longer worry about whether they took their pill or whether food interfered with absorption. For people with absorption problems or inconsistent hormone control, weekly delivery offers real medical benefits beyond psychology.
The same pattern appears in weight loss medications. Semaglutide, sold as Ozempic for diabetes and Wegovy for weight loss, has a half-life of about one week, which is why the injectable form works once weekly. In landmark studies, people using semaglutide with lifestyle changes lost about 15 percent of their body weight over 68 weeks, compared to about 6 pounds for those without medication. The weekly dosing made this possible and improved adherence compared to daily alternatives.
But weekly dosing reveals something deeper about drug delivery science. It requires understanding how drugs behave in the body over extended periods. A medication that lasts one week needs a different formulation than one lasting one day. Researchers must ensure the drug releases gradually, maintaining therapeutic levels without dangerous peaks and valleys.
This is where advanced coating technologies enter the picture. Scientists are developing depot systems that release medications at controlled rates. One experimental approach uses atomic precision coatings to create once-monthly treatments. A single injection of liraglutide, a diabetes medication normally requiring daily injections, maintained therapeutic blood levels for up to 42 days in testing. The coating prevented the drug from dumping into the bloodstream all at once. Instead, it released gradually over weeks, keeping drug concentrations in the optimal therapeutic window.
This smooth release profile offers medical advantages. When GLP-1 receptor agonists like liraglutide are given in high doses, they commonly cause nausea and other gastrointestinal side effects. A gradual release avoids these peaks, improving tolerability while maintaining effectiveness. The patient gets the same clinical benefit with fewer side effects.
The implications extend beyond convenience. Weekly and monthly treatments reveal that our bodies can maintain health with less frequent dosing than we assumed. This challenges the traditional model of daily medication. It suggests that many chronic conditions don’t require constant drug presence but rather sustained therapeutic levels. The difference is subtle but important.
Adherence improves dramatically with less frequent dosing. Changing from daily to weekly injections has been shown to significantly improve adherence in diabetes management, and this behavior persists over time. When patients take medication once weekly instead of daily, they’re more likely to stay consistent. This consistency translates to better health outcomes.
The development of these treatments also reveals how patient preferences drive innovation. Pharmaceutical companies investing in once-weekly formulations aren’t just chasing novelty. They’re responding to real feedback from people managing chronic diseases. Patients want treatments that fit into their lives, not treatments that demand their lives revolve around medication schedules.
Looking forward, the trend toward less frequent dosing will likely accelerate. Several new weight loss medications in advanced development stages are being designed as oral daily pills or weekly injections. Orforglipron, in advanced development stages, may be approved by March 2026 as an oral capsule taken once daily. Eloralintide, given as a weekly injection, showed patients losing up to 20 percent of body weight after 48 weeks in Phase 2 studies.
These treatments teach us that drug delivery isn’t just about getting a chemical into the body. It’s about understanding how that chemical behaves over time, how the body processes it, and how patients will actually use it. Once-weekly treatments work because they align with human behavior while maintaining the science of pharmacology. They reduce the gap between what doctors prescribe and what patients actually do.
The future of medicine may not be about more powerful drugs but about smarter delivery. A medication that works once weekly is often the same chemical as one requiring daily doses, just formulated differently. The innovation lies in understanding the body’s needs and the patient’s reality, then engineering a solution that serves both.
Sources
https://www.goodrx.com/conditions/weight-loss/new-weight-loss-drugs
