# Presence of Sildenafil and Tadalafil in Herbal Medicinal Products Claimed to Treat Erectile Dysfunction in Nyamagana and Ilemela Districts, Mwanza, Tanzania

## TL;DR

This study found that many herbal products in Tanzania claiming to treat erectile dysfunction are contaminated with prescription drugs like sildenafil and tadalafil.

## Contribution

The study provides new evidence of pharmaceutical adulteration in herbal aphrodisiacs in Tanzania using HPTLC analysis.

## Key findings

- 62.5% of 40 herbal samples were found to be adulterated with sildenafil, tadalafil, or both.
- 14 samples (56% of adulterated) contained both sildenafil and tadalafil.
- Two samples exceeded the maximum recommended daily dose of sildenafil (100 mg).

## Abstract

Background: Herbal products are increasingly utilized for various conditions, including erectile dysfunction (ED), due to their minimal side effects, affordability, and natural properties. Phosphodiesterase type 5 inhibitors (PDE 5is) such as sildenafil citrate, tadalafil, vardenafil hydrochloride, and avanafil are synthetic oral medications approved for ED treatment. However, multiple studies have highlighted the contamination of herbal aphrodisiacs with PDE 5i or their conventional analogs. This study evaluated the contamination of aphrodisiac-claimed herbal products available in Mwanza, Tanzania.

Method: A total of 40 herbal product samples were collected from local vendors and analyzed by high-performance thin layer chromatography (HPTLC). Chromatography was performed on a 20 × 10 cm aluminum-backed plate coated with analytical-grade silica gel 60 F254. The plates were developed on a 20 × 20 cm 30-min presaturated twin trough tank containing chloroform (9 mL), methanol (1 mL), and diethylamine (0.1 mL) as the mobile phase. The developed plates were scanned at the wavelengths of 292 and 284 nm for sildenafil and tadalafil, respectively.

Results: Out of 40 herbal product samples analyzed, 25 samples (62.5%) were found to be adulterated. Among the adulterated samples, 2 (8%) were contaminated with sildenafil, 9 (36%) with tadalafil, and 14 (56%) with both sildenafil and tadalafil. Quantitative analysis indicated that two samples (12.5%) of the sildenafil-adulterated samples contained an amount of sildenafil that exceeded the maximum recommended daily dose of 100 mg.

Conclusion: Aphrodisiac-claimed herbal medicinal products are adulterated with conventional medicines, sildenafil and tadalafil. Alarmingly, some of these products contain higher amounts of these pharmaceutical agents beyond the maximum daily dose.