Generic PrEP bought online for UK use is validated by drug testing service

Simon Collins, HIV i-Base

A useful study for people using generic PrEP that they have bought online was presented by Nneka Nwokolo from the NHS sexual health clinic at 56 Dean Street in London. [1]

This study included testing plasma samples for active levels of both tenofovir and emtricitabine from HIV negative people attending the Dean Street clinic. It was based on a clinic that was set up in February 2016 in response to increasing numbers of patients who were buying generic PrEP online.

Although the NHS was not able to prescribe PrEP, some clinics have launched free services to enable people to receive appropriate monitoring if they are buying PrEP online. This included the option to provide a blood sample to test for drug levels.

Overall, 234 gay men were registered at the PrEP clinic and 212 people provided samples for this analysis. Median age was 37 (IQR 31-45), 85% were Caucasian and 35% used chemsex drugs (meth, meph or G). Daily PrEP was used by most people (85%) with only 15% using event-based dosing. The majority of men (92%) had bought PrEP because of information and links provided on a community website (, with most using one of two recommended suppliers (predominantly Cipla’s Tenvir-EM).

Drug levels were measured in plasma using HPLC with UV detection, with a sensitivity range of 25 to 10,000 ng/mL.

The median (range) levels of plasma TFV and FTC were 103 ng/mL (range: 21 to 597 ng/mL) and 142 ng/mL (17 to 1876 ng/mL), respectively. Median time post-dose for sampling was 15.5 hours (range 0.5 to 27). At 24-hours post-dose, all levels were above median minimum 24-hour targets of 19 ng/mL and 22 ng/mL, for TFV and FTC respectively, based on historical data.

Other safety monitoring results included that baseline eGFR was normal in all participants with paired samples. STIs were diagnosed at baseline or within three months in a quarter of the group (n=39, 26%). An additional 13 people had an STI at a follow-up visit. No new cases of HIV were detected from 58 person-years of follow-up (median 91 days per person).


The study was set up to check whether some internet suppliers (currently recommended by community websites like HIV i-Base and are reliable sources for genuine generic medicines. [2, 3]

The results were overwhelmingly positive.

The study was not set up to check generic formulations per se as the quality of FDA pre-qualified and WHO-approved generics is already well established.

Until the NHS provide PrEP, and this might not be widely until generic TDF/FTC is available, the study provides important validation that the websites used by the participant were selling genuine generics and not fake.


  1. Wang X et al. InterPrEP: internet-based pre-exposure prophylaxis (PrEP) with generic tenofovir DF/emtricitabine (TDF/FTC) in London analysis of pharmacokinetics, safety and outcomes. Oral abstract O315.
  2. HIV i-Base Q&A. “Where can I buy PrEP or HCV meds online and is it legal in the UK?” (15 September 2015).
  3. “Buy PrEP now”. (Accessed 31 October 2016).

Links to other websites are current at date of posting but not maintained.