Zoely is a combined oral contraceptive containing nomegestrol acetate, a highly selective progestogen, and estradiol, a natural oestrogen. Nomegestrol acetate has no oestrogenic, androgenic, glucocorticoid or mineralocorticoid activity.1
The safety and efficacy of the estradiol/nomegestrol combination were assessed in two open-label phase III trials, one conducted in Europe and one performed in the US. Participants were randomised to receive 1.5mg estradiol/2.5mg nomegestrol acetate or 30 microgram ethinylestradiol/3mg drospirenone (Yasmin).1
In women aged ≤35 years in the European trial (n=1,757), Pearl Indices (pregnancies per 100 woman-years) were:
- 0.38 (95% CI 0.10–0.97) for estradiol/nomegestrol, compared with
- 0.81 for ethinylestradiol/drospirenone (95% CI 0.17–2.35).2
In the US study, Pearl Indices in the same age group (n=1,838) were 1.27 (95% CI 0.66–2.22) and 1.89 (95% CI 0.69–4.11), respectively.3
The estradiol/nomegestrol combination was well tolerated in both studies, with acne and irregular withdrawal bleeding the most common adverse effects.1–3
- Zoely Summary of Product Characteristics, August 2012.
- Mansour D et al. Eur J Contracept Reprod Health Care 2011; 16; 430–43.
- Westhoff C et al. Obstet Gynecol 2012; 119: 989–999.