LIB-01

What is LIB-01?#

LIB-01 is a first-in-class oral compound under development by Swedish company Dicot Pharma for the treatment of erectile dysfunction (ED) and premature ejaculation. The active pharmaceutical ingredient is a synthetic analog of libiguin, a phragmalin limonoid originally isolated from the root bark of Neobeguea mahafalensis, a tree native to Madagascar that has been used in traditional medicine for treating sexual dysfunction.

LIB-01 represents a fundamentally new approach to ED treatment. Rather than acting on peripheral vasculature like PDE5 inhibitors (sildenafil/Viagra, tadalafil/Cialis), LIB-01 modulates melanocortin-4 receptor (MC4R) signaling pathways in the central nervous system, engaging the brain's own sexual arousal circuitry. This mechanism is conceptually related to bremelanotide (PT-141), an injectable melanocortin receptor agonist approved for hypoactive sexual desire disorder, but LIB-01 achieves oral bioavailability and a dramatically longer duration of action.

The most remarkable characteristic of LIB-01 is its pharmacodynamic profile: a single 3-day oral treatment course produces sustained improvement in erectile function lasting 4 to 8 weeks. This is entirely unique in the ED field and suggests a mechanism involving long-term receptor or pathway modulation rather than simple receptor occupancy.

Mechanism of Action#

LIB-01 modulates the melanocortin-4 receptor (MC4R) pathway in the brain and spinal cord. The melanocortin system plays a critical role in regulating sexual arousal, erectile function, and ejaculatory control through descending neural pathways from the hypothalamus to the spinal erection centers.

Central MC4R Pathway#

• MC4R upregulation: Preclinical data suggest that LIB-01 enhances endogenous melanocortin signaling by upregulating MC4R expression and increasing production of the receptor's natural agonist alpha-MSH, rather than directly and transiently activating the receptor like bremelanotide
• Spinal cord integration: MC4R signaling in the lumbosacral spinal cord facilitates the pro-erectile reflex arc, coordinating parasympathetic outflow to penile vasculature
• Hypothalamic modulation: Central MC4R activation in the hypothalamus integrates sexual arousal signals with autonomic nervous system output

Duration of Action#

The sustained 4-8 week effect from a 3-day dosing course is attributed to LIB-01's mechanism of MC4R pathway modulation rather than direct receptor occupancy. The compound's short plasma half-life combined with its prolonged pharmacodynamic effect suggests lasting changes in receptor expression or downstream signaling cascade sensitivity. In preclinical studies with libiguins A and B, effects on mounting behavior in rodents persisted for up to 11 days after a 3-day treatment period at doses as low as 0.004 mg/kg/day.

Research Overview#

LIB-01's development is based on the discovery of libiguins A and B, novel phragmalin limonoids identified by Professor Jarl Wikberg in collaboration with Dr. Philippe Rasoanaivo during ethnopharmacological research in Madagascar. The Phase 1 first-in-human study (2023) demonstrated safety, tolerability, and a clear pro-erectile signal with unique pharmacodynamics. The Phase 2a study (2024-2025) confirmed efficacy in 156 men with ED, with a Phase 2b study planned for 2026.

Preclinical studies also suggest potential applications beyond sexual dysfunction, with early investigations into metabolic disease areas including obesity and diabetes.

Important Considerations#

• LIB-01 is an investigational compound not approved for clinical use in any jurisdiction
• All clinical data are from early-phase trials with limited sample sizes
• The compound is technically a small molecule limonoid, not a peptide, though it acts on the melanocortin receptor system shared with peptide therapeutics
• No long-term safety data are available beyond the 8-week Phase 2a observation period
• Dicot Pharma is developing LIB-01 through regulated clinical trials; it is not available as a research peptide

Key Research Findings#

Results of a First-in-Human Trial of LIB-01, a Novel, First in Class Potential Oral ED Drug with Unique Pharmacodynamic Properties, published in Journal of Sexual Medicine (Dicot Pharma investigators, 2024):

• The study showed unique pharmacodynamic profile with onset within 7 days of 3-day dosing course

Phase 2a Trial Results: LIB-01 Improves Erectile Function with Sustained Effect, published in Conference presentation (October 2025) (Dicot Pharma investigators, 2025):

• The study demonstrated complete responders of 31% vs 0% placebo

Related Reading#

• LIB-01 research studies and evidence
• LIB-01 dosing protocols
• LIB-01 side effects profile
• Melanotan-2 research guide
• PT-141 research guide