Fezolinetant (VEOZAH™) is an oral, small molecule, neurokinin 3 receptor (NK3R) antagonist, which is being developed by Astellas Pharma Inc. for the treatment of moderate to severe vasomotor symptoms (VMS) or hot flashes due to menopause. Inhibiting NK3R-mediated signaling in the central nervous system is a non-hormonal strategy to modulate the activity of neurons that are associated with thermoregulation, thereby reducing the frequency and severity of VMS. VEOZAH is a neurokinin 3 (NK3) receptor antagonist that blocks neurokinin B (NKB) binding on the kisspeptin/neurokinin B/dynorphin (KNDy) neuron to modulate neuronal activity in the thermoregulatory center. Fezolinetant has a high affinity for the NK3 receptor (Ki value of 19.9 to 22.1 nmol/L), which is more than 450-fold higher than the binding affinity to NK1 or NK2 receptors. Fezolinetant received its first approval in the USA in May 2023 for the treatment of moderate to severe VMS due to menopause.

Naldemedine (Symproic) is an opioid antagonist indicated for the treatment of opioid-induced constipation (OIC) in adult patients with chronic non-cancer pain. Naldemedine is an opioid antagonist with binding affinities for mu-, delta-, and kappa-opioid receptors. Naldemedine functions as a peripherally-acting mu-opioid receptor antagonist in tissues such as the gastrointestinal tract, thereby decreasing the constipating effects of opioids. Naldemedine is a derivative of naltrexone to which a side chain has been added that increases the molecular weight and the polar surface area, thereby reducing its ability to cross the blood-brain barrier (BBB). Naldemedine is also a substrate of the P-glycoprotein (P-gp) efflux transporter. Based on these properties, the CNS penetration of naldemedine is expected to be negligible at the recommended dose levels, limiting the potential for interference with centrally-mediated opioid analgesia. Naldemedine was approved in 2017 in both the US and Japan for the treatment of Opioid-induced Constipation.

Ulipristal acetate (also known as CDB-2914 and PGL4001 and trade name Ella in the U.S) is a novel oral emergency contraceptive designed and developed by HRA Pharma. It is a selective progesterone receptor modulator, which reversibly blocks the progesterone receptors in target tissues it was approved in May 2009 by the European Commission and in August 2010 by the FDA as safe and effective in preventing unintended pregnancy for up to 120 hours – or five days – post- unprotected intercourse or contraceptive failure. Ella is not intended for routine use as a contraceptive. When taken immediately before ovulation is to occur, ella postpones follicular rupture. The likely primary mechanism of action of ulipristal acetate for emergency contraception is therefore inhibition or delay of ovulation; however, alterations to the endometrium that may affect implantation may also contribute to efficacy. The most common side effects are: headache, nausea, stomach (abdominal) pain, menstrual pain. Some women taking ella may have their next period earlier or later than expected. If your period is more than a week late, you should get a pregnancy test.

Medroxyprogesterone acetate (INN, USAN, BAN), also known as 17α-hydroxy-6α-methylprogesterone acetate, and commonly abbreviated as MPA, is a steroidal progestin, a synthetic variant of the human hormone progesterone. Medroxyprogesterone acetate (MPA) administered orally or parenterally in the recommended doses to women with adequate endogenous estrogen, transforms proliferative into secretory endometrium. Androgenic and anabolic effects have been noted, but the drug is apparently devoid of significant estrogenic activity. While parenterally administered MPA inhibits gonadotropin production, which in turn prevents follicular maturation and ovulation, available data indicate that this does not occur when the usually recommended oral dosage is given as single daily doses. MPA is a more potent derivative of its parent compound medroxyprogesterone (MP). While medroxyprogesterone is sometimes used as a synonym for medroxyprogesterone acetate, what is normally being administered is MPA and not MP. Used as a contraceptive and to treat secondary amenorrhea, abnormal uterine bleeding, pain associated with endometriosis, endometrial and renal cell carcinomas, paraphilia in males, GnRH-dependent forms of precocious puberty, as well as to prevent endometrial changes associated with estrogens. Progestins diffuse freely into target cells in the female reproductive tract, mammary gland, hypothalamus, and the pituitary and bind to the progesterone receptor. Once bound to the receptor, progestins slow the frequency of release of gonadotropin releasing hormone (GnRH) from the hypothalamus and blunt the pre-ovulatory LH surge.

Endoxifen, also known as N-desmethyl-4-hydroxytamoxifen, is active metabolites of tamoxifen. This metabolite exhibits a 100-fold higher binding affinity to the estrogen receptor (ER) and are more effective in suppressing cell proliferation than tamoxifen. In humans, the conversion from tamoxifen to endoxifen is predominant. Endoxifenis is an orally active, selective estrogen receptor modulator (SERM) that was developed for the treatment of estrogen receptor-positive breast cancer. In addition, this drug possesses antimanic properties, what can be used in the treatment of patients with bipolar I disorder (BPD I).