A spike in adverse event reports and online alarm triggered the review. See what it found.
Australia’s medicines regulator has confirmed lisdexamfetamine dimesilate is safe, effective and compliant with manufacturing standards, following an investigation into a sudden rise in adverse event reports earlier this year.
The Therapeutic Goods Administration began its review in March 2025 after receiving an unexpected increase in reports of lack of effectiveness, quality issues and other safety concerns related to the drug (known commercially as Vyvanse).
Lisdexamfetamine dimesilate is approved for use in the treatment of attention deficit hyperactivity disorder and moderate to severe binge eating disorder in adults when nonpharmacological treatment is unsuccessful or unavailable.
The spike in reports coincided with widespread social media commentary and prompted further laboratory testing of multiple batches.
“Our testing found that all batches tested were compliant with expected strengths and quality,” the TGA said in a statement.
Between January and August 2025, the TGA received 382 adverse event reports for lisdexamfetamine dimesilate.
The most reported adverse event terms included drug ineffective (190 cases), anxiety (100 cases), product label issue (94 cases), therapeutic response decreased (78 cases), insomnia (70 cases), condition aggravated (65 cases), disturbance in attention (62 cases), therapeutic product effect decreased (56 cases), fatigue (54 cases) and irritability (47 cases).
The monthly number of all lisdexamfetamine dimesilate adverse event reports received peaked at 150 in April 2025 (75 reported as “drug ineffective”) and has been decreasing since then with 24 total reports in August 2025 (15 reported as “drug ineffective”).
The TGA has advised health professionals to be aware that patients may raise concerns following the online commentary. Clinicians were encouraged to reassure patients that testing has found no problems with lisdexamfetamine dimesilate’s quality, safety or effectiveness.
The TGA has also recommended they continue prescribing in line with the approved indications.
Related
The TGA said its review of the case reports found that most of the reported adverse event terms were already listed in the medicine’s Australian product information. See here for more details.
Of the terms not listed in the Australian PI, some were related to two typographical errors on the label, some were related to the underlying condition (ADHD), and some were concerns about lack of effectiveness.
The concern for lack of effectiveness was referred to TGA laboratories for further testing, where all six different strengths (20mg, 30mg, 40mg, 50mg, 60mg and 70mg) were tested for active ingredient, the levels of any related substances or impurities, dissolution, and uniformity of dosage units.
“All six samples complied with the requirements of the tests for content of the active ingredient, levels of impurities, dissolution and uniformity of dosage units,” the TGA reported.
In relation to the typographical errors, these were related to the packaging, which stated:
- “Each capsules contain…” whereas the correct wording should be “Each capsule contains…”; and
- The company name includes the misspelled word “Pharmaceutivals”, which should be “Pharmaceuticals”.
“These minor errors have led to customer complaints, concerns being raised in social media and an increase in reports of suspected adverse events,” the TGA said in an alert in April.
The alert informed patients and carers that the typographical errors did not impact the quality of the lisdexamfetamine dimesilate capsules or patient safety and advised patients to continue taking the drug as prescribed.
The full laboratory reports are available here.
