Zimbabwean contraceptives a hit in South Africa

Every month, Nancy (not her real name) and her business partner travel to Zimbabwe to stock up on Marvelon family planning pills. She smuggles them back into South Africa, where she sells them at a healthy profit to other Zimbabweans who for various reasons don't want the contraceptive pills dispensed in South African clinics.
Nancy's suppliers are hospital staff in Zimbabwean hospitals who sell the pills to her for R5 a blister pack. Marvelon is distributed at hospitals, clinics and pharmacies through the Family Planning Council of Zimbabwe which is supplied by UNICEF.
Sometimes Nancy hides the pills in her clothes and luggage, but usually she pays bus drivers and cross-border taxi drivers R1 per blister pack of 28 pills to transport them for her.
If she runs short of stock, she buys packets for R10 from a "wholesale" supplier in Johannesburg who also illegally imports the pills from Zimbabwe.
Nancy says she has a 100 customers a month in Springs alone, and she sells the packets for R20 to bulk buyers or R30 to individuals. 
By contrast, GroundUp found that Marvelon tablets sold for about R130 per 28 tablets in Johannesburg pharmacies. Although contraception is free at public health facilities, the drug supplied is Oralcon.
"We also supply other people who sell in places like Daveyton, Tsakane, Duduza [where her business partner operates], Nigel and Brakpan. We also advertise through our Apostolic Church, which has many branches," says Nancy.
Nancy used to be a teacher. She has a small vegetable stall, but with two children at university and two at high school in Zimbabwe, she struggled to make ends meet. "My husband is sick and has not worked for a long time," she says.
The contraceptives are also smuggled to Botswana and Namibia. Nancy sells mostly to Zimbabwean immigrants, but among her customers are also immigrants from Mozambique, Lesotho and Malawi.
One woman says she has been buying from Nancy for 18 months. "When I asked for the pills I used to use in Zimbabwe at the local clinic in KwaThema, they said they do not have them," she says.
Another one of Nancy's customers said, "A nurse told me to go to Zimbabwe if I want those pills, because they do not have them. I can't go to Zimbabwe just for contraceptives. They gave me other pills. I did not like them very much, because I had used the other type for a long time. I then decided to buy the ones they bring from Zimbabwe."
Other women told GroundUp they bought from Nancy to avoid the long queues at the local clinics and they believed the local pills were "low grade". (Actually the Oralcon pills supplied in South African clinics are fine, though people often experience minor side-effects when they switch to new drugs.)
 Marvelon versus Oralcon - is there any difference?
South African public health facilities supply women the contraceptive Oralcon at no charge. It appears Marvelon, which can be bought in South African pharmacies, is the drug supplied in the Zimbabwean health system.  What's the difference between these two drugs?
The answer is not much at all.
The active ingredients in Marvelon are desogestrel and ethinylestradiol. The active ingredients in Oralcon are levonorgestrel and ethinylestradiol, at exactly the same doses. In other words the only difference is that Marvelon contains desogestrel, while Oralcon contains levonorgestrel.
So what's the difference between desogestrel and levonorgestrel. Dr Jeff Livingston explains on HealthTap: "These are simply two different forms of the hormone progesterone. Clinically the differences for the person taking it are undetectable." 
From the point of view of a woman taking them, Oralcon and Marvelon are virtually the same drug.