In short
Thioctic acid, also known as alpha-lipoic acid, is a chemically synthesised substance that acts as an antioxidant in the body. It is already authorised as a medicine in Austria under the trade name Thiogamma 600 mg Filmtabletten. A Phase 2 trial (2025-521985-82-00) is currently authorised to study whether a 16-week combined treatment with thioctic acid and benfotiamine improves symptoms of diabetic sensorimotor polyneuropathy in 136 participants.
Key points
- Thioctic acid is a chemical substance also known as alpha-lipoic acid, authorised as a medicine in Austria.
- It is being studied as a comparator in a Phase 2 trial for diabetic sensorimotor polyneuropathy.
- The trial 2025-521985-82-00 is authorised and plans to enrol 136 participants.
- Treatment lasts 16 weeks and combines thioctic acid with benfotiamine.
- The main measure is the change in neuropathy symptom characteristics from baseline to day 112.
- Thioctic acid is taken as a 600 mg film-coated tablet by mouth in this trial.
What is thioctic acid?
KG. In the registered clinical trial, thioctic acid appears as a comparator, meaning it serves as the reference treatment against which the combined therapy is measured. Other names for the same substance include 6,8-thioctic acid, tioctic acid, and lipoic acid.
How does thioctic acid work?
Thioctic acid is a naturally occurring compound that acts as a cofactor for mitochondrial enzymes involved in energy metabolism. It functions as a powerful antioxidant, helping to neutralise harmful free radicals that can damage nerve cells. In conditions like diabetic neuropathy, oxidative stress is thought to contribute to nerve damage, and thioctic acid's antioxidant properties are believed to help protect nerves from this damage.
Which conditions is it used or studied for?
- Diabetic sensorimotor polyneuropathy (DSPN) — a type of nerve damage caused by diabetes that leads to pain, tingling, and numbness, mainly in the feet and legs. The registered trial is studying whether thioctic acid combined with benfotiamine improves these symptoms.
How is thioctic acid given?
In the registered trial, thioctic acid is given as a film-coated tablet for oral use. The product used is Thiogamma 600 mg Filmtabletten, a 600 mg tablet. The dm+d browser also lists thioctic acid 50 mg capsules as a discontinued medicinal product form.
What do the clinical trials show?
One clinical trial is registered in the EU Clinical Trials Information System. The trial 2025-521985-82-00 is a Phase 2, prospective, randomised, controlled, parallel-group, double-blind, double-dummy, 3-arm study. It is currently authorised and plans to enrol 136 participants with diabetic sensorimotor polyneuropathy. The study compares a 16-week combined treatment of thioctic acid and benfotiamine against each drug alone and against the pooled monotherapies. The primary outcome is the change from baseline to day 112 in neuropathy symptom characteristics.
What side effects are known?
According to a safety assessment by the Technical University of Denmark, studies in patient groups taking alpha-lipoic acid at doses from 300 to 1800 mg per day have reported adverse effects including allergic skin reactions such as hives and itchiness, gastrointestinal symptoms such as stomach ache, nausea, vomiting and diarrhoea, and dizziness. These studies were not designed to investigate adverse effects, so the full side effect profile is not fully characterised.