South African Male User Research on Acceptability of Implants and Injections (SAMURAI).


Our prior formative research in Cape Town, South Africa, revealed a strong willingness among young people, both male and female, to use injectable and implantable HIV prevention products. Through the iPrevent Discrete Choice Experiment (DCE), our team found that men, in particular, showed significant interest in Long-acting (LA) delivery methods. Specifically, 67% of heterosexual men and MSM preferred a 6-month implant over a bimonthly injection, compared to only 52% of women.

Utilizing placebo crossover studies offers a valuable means to assess end-user preferences based on actual product choice and usage, providing insights that are more applicable to real-world scenarios than traditional clinical trials. This approach also allows us to evaluate product acceptability and implementation considerations for early-stage development or unlicensed yet effective products. By incorporating placebos, men can experience using these dosing platforms, offering insights beyond hypothetical attitudes. Similar shifts in opinions were observed in our previous Trio and Quatro studies after participants used novel HIV prevention methods.

Our study design focuses on delivery form attributes independently of drug-related effects or efficacy, offering an innovative balance between implant use with longer intervals and more frequent visits for injections, mirroring potential real-world scenarios. This method enables us to gather crucial information on acceptability and safety, contributing significantly to product development, testing, and eventual roll-out.

The objective of the DCE is to deepen our understanding of men’s acceptability of LA products by rigorously assessing preferences and trade-offs, complementing experiential acceptability evaluations during the clinical phase. Ultimately, our goal is to develop an HIV prevention method that is not only effective but also well-liked and consistently used by men worldwide, including heterosexual and MSM individuals, thereby making a substantial impact on global public health.

This study poses minimal to moderate risks to participants, as no pharmaceutical drugs are involved, and implant insertions are considered moderate clinical procedures, while injections are minor. The knowledge gained from this research will significantly contribute to understanding men’s willingness and ability to use implants for HIV prevention, with a specific focus on comparing implant acceptability to injections.


  • Wits RHI
  • Prof Thesla Palanee-Phillips (Co-Principal Investigator)
  • Dr Nkosiphile Ndlovu (Co-Principal Investigator)

Other Partners & Collaborators

  • Desmond Tutu Health Research Foundation
  • Dr Katherine Margaret Kill (Principal Investigator)
  • Women’s Global Health Imperative at RTI International
  • Elizabeth Montgomery (Principal Investigator)
  • Alexandra Minnis (Co-Principal Investigator)

Latest Update

April 2024

For more details about SAMURAI please email

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