One shot a week: How weekly Parkinson’s injection would be a game-changer for patients

Imagine swapping the burden of multiple daily pills for a single, simple injection once a week – no more worrying over dosages, missing medication, or the rollercoaster “on‑off” symptom swings.Recent research from the University of South Australia has unveiled a novel, biodegradable gel combining levodopa and carbidopa, delivering steady therapeutic levels across seven days. This innovative long‑acting injectable maintains consistent drug delivery, reduces side effects, and transforms adherence, offering real‑world relief for millions living with Parkinson’s disease.Read on to know more about the hopeful discovery.

What is Parkinson’s?

Parkinson's disease is a progressive neurological disorder that primarily affects movement. It is characterized by the degeneration of nerve cells in the brain, specifically those producing dopamine, a neurotransmitter crucial for coordinating movement. This leads to a range of symptoms, including tremors, stiffness, and slowness of movement. While there is no cure, treatments and therapies can help manage symptoms and improve quality of life.

Globally, Parkinson's disease (PD) affects millions.A study published in The BMJ in March 2025 projects that 25.2 million people will be living with Parkinson's by 2050.

The current “gold standard” treatment – levodopa combined with carbidopa – must be taken 3–5 times daily due to its short half-life. For elderly patients or those with dysphagia, frequent dosing leads to missed pills, inconsistent dopamine blood levels, and disruptive motor fluctuations (the dreaded “on/off” periods)

The breakthrough:

What comes as a breakthrough is a biodegradable implant (an in‑situ forming gel) from the researchers at the University of South Australia (UniSA).

The researchers designed a long-acting shot that supplies a steady, seven-day dose of levodopa and carbidopa, the two main medicines used to control Parkinson’s symptoms.A once-a-week injection could greatly ease life for the more than eight million people who live with Parkinson’s disease by replacing the daily routine of swallowing multiple pills.Details of their work appeared in the journal Drug Delivery and Translational Research.

Cutting down the burden:

Parkinson’s is the second most common neurological condition worldwide, impacting over 8.5 million people.

Currently, patients often need to take oral medications multiple times a day to manage symptoms like tremors and stiffness. This can be tough, especially for older adults or those who struggle to swallow tablets. Inconsistent dosing can lead to fluctuations in drug levels and unwanted side effects.However, with this latest innovation, scientists have tapped into a new solution – an exciting new injectable treatment for Parkinson’s disease – that could change the lives of millions.

This innovative formulation is made from biodegradable materials and is injected just under the skin or into muscle, slowly releasing medication over an entire week.

What are the advantages?

Extensive lab tests have shown impressive results: over 90% of levodopa and more than 81% of carbidopa were released over seven days. The implant broke down by over 80% within a week and showed no significant toxicity in safety tests. Plus, it can be easily administered with a fine needle, meaning less discomfort and no need for surgery.

The benefits?Stable symptom control: Maintaining consistent dopamine levels helps avoid the peaks/troughs that exacerbate tremors and rigidity, bringing smoother and more predictable control over motor symptoms.Improved patient experience: Only one weekly injection versus juggling multiple daily pills, a major win for those with swallowing issues or cognitive decline.Reduced side effects: Stable dosing can minimize side effects related to dopamine level fluctuations, like dyskinesia and “off” episodes.Minimally invasive: Using a simple subcutaneous injection avoids the need for pumps or surgery, making this approach accessible and less risky.

The experts’ take:

As per SciTech Daily, lead researcher Professor Sanjay Garg from the University of South Australia’s Centre for Pharmaceutical Innovation said, “Our goal was to create a formulation that simplifies treatment, improves patient compliance, and maintains consistent therapeutic levels of medication.

This weekly injection could be a game-changer for Parkinson’s care.” He emphasized that while levodopa is the standard treatment, its short lifespan means patients have to take it several times a day.UniSA PhD student Deepa Nakmode added that this new implant is designed to release both levodopa and carbidopa steadily over one week. “After years of focused research, it’s incredibly rewarding to see our innovation in long-acting injectables for Parkinson’s disease reach this stage.

Our invention has now been filed for an Australian patent,” she said.The injectable gel combines two polymers to ensure controlled and sustained drug release, making treatment easier and more effective for patients.

What’s ahead?

It doesn’t need any more emphasizing that this latest discovery offers hope for Parkinson’s patients. Professor Garg notes, “The implications of this research are profound. By reducing the frequency of dosing from multiple times a day to a weekly injection is a major step forward in Parkinson’s therapy. We’re not just improving how the drug is delivered; we’re improving patients’ lives.” He believes this technology could also help treat other chronic conditions such as cancer, diabetes, and neurodegenerative disorders.The team hopes to begin clinical trials soon and is exploring ways to bring this innovation to patients.