Viprostol

Viprostol
Clinical data
Other names	CL-115347; CL115347; CL-115,347; 15-(Deoxy)-16-hydroxy-16-vinylprostaglandin E2 methyl ester; 15-Deoxy-16-hydroxy-16-vinyl-PGE2 methyl ester; DHV-PGE2Me
Routes of; administration	Topical
Drug class	Prostaglandin E2 analogue
ATC code	None;
Identifiers
	IUPAC name methyl (Z)-7-[(1R,2R,3R)-2-[(E)-4-ethenyl-4-hydroxyoct-1-enyl]-3-hydroxy-5-oxocyclopentyl]hept-5-enoate;
CAS Number	73621-92-8 ; 73647-73-1;
PubChem CID	6438370;
ChemSpider	4942852;
UNII	O2Y6I4Y8TF;
KEGG	D06310;
ChEBI	CHEBI:231014;
ChEMBL	ChEMBL2107669;
CompTox Dashboard (EPA)	DTXSID301021620 ;
Chemical and physical data
Formula	C23H36O5
Molar mass	392.536 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES CCCCC(C/C=C/[C@H]1[C@@H](CC(=O)[C@@H]1C/C=C\CCCC(=O)OC)O)(C=C)O;
	InChI InChI=1S/C23H36O5/c1-4-6-15-23(27,5-2)16-11-13-19-18(20(24)17-21(19)25)12-9-7-8-10-14-22(26)28-3/h5,7,9,11,13,18-19,21,25,27H,2,4,6,8,10,12,14-17H2,1,3H3/b9-7-,13-11+/t18-,19-,21-,23?/m1/s1; Key:TWCQWABAGCMHLL-ROVQGQOSSA-N;

Viprostol (INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name, BANTooltip British Approved Name; developmental code name CL-115347) is a synthetic prostaglandin E2 (PGE₂) analogue which was under development for the treatment of alopecia (hair loss) but was never marketed.^[1]^[2]^[3]^[4] It is administered topically and was found to increase scalp hair growth in people with alopecia, albeit with mixed evidence of effectiveness.^[1]^[2] The drug was under development by American Cyanamid.^[3] It reached phase 3 clinical trials for treatment of alopecia in the 1980s, but development was discontinued due to inadequate effectiveness.^[3]^[5] Viprostol is also a vasodilator and was originally developed for the treatment of hypertension in the mid-1970s before being repurposed for alopecia.^[4]

References

1 2 Roenigk HH (1988). "New topical agents for hair growth". Clinics in Dermatology. 6 (4): 119–121. doi:10.1016/0738-081x(88)90075-2. PMID 3214817.
1 2 Koh WL, Sinclair R (2026). "Minoxidil". Hair Loss. Updates in Clinical Dermatology. Cham: Springer Nature Switzerland. pp. 211–221. doi:10.1007/978-3-032-24862-6_18. ISBN 978-3-032-24861-9. Topical viprostol, a PGE2 analogue, can increase human hair growth and terminal hairs, although studies regarding its efficacy are conflicting [14].
1 2 3 The Pink Sheet (18 July 1988). "Proanagen's Diazoxide-Based Hair Growth Product Beginning Efficacy". Citeline. Insights. Retrieved 27 July 2026. Another potential minoxidil competitor was recently abandoned when American Cyanamid halted Phase III trials of viprostol due its "modest response rate . . . and the cost of further studies" ("The Pink Sheet" April 25, T&G-10). Cyanamid's Shulton subsidiary subsequently announced plans to launch a line of mass market cosmetic thinning hair products in early 1989.
1 2 Sansing J (10 August 1987). "Minoxidil Falls Short as Miracle Baldness Cure". Los Angeles Times. Retrieved 27 July 2026. American Cyanamid, a large pharmaceutical firm, is testing Viprostol at several locations nationwide, including the Washington Hospital Center. Similar to Minoxidil, Viprostol is a vasodilator, expanding blood vessels and facilitating blood flow. Developed in the mid-1970s for hypertension, it was never marketed. Now, working on the same hypothesis as that of Upjohn--that increased blood supply to the scalp aids hair growth--American Cyanamid has geared up for the costly and time-consuming FDA-approved human testing. Preliminary results are expected shortly.
↑ The Pink Sheet (25 April 1988). "Lederle Discontinuing Viprostol Baldness Studies, Will Go Cosmetic". Citeline. Insights. Retrieved 27 July 2026. Lederle discontinuing viprostol baldness studies, will go cosmetic route to a product for hair thinning, American Cyanamid noted in an April 19 press release reporting the firm's first quarter financial results. [...] "The study included the vasodilator viprostol, a carrier lotion and a placebo, [and] the individual differences in the results were not sufficiently significant to warrant further effort on viprostol." In late 1986, Lederle enrolled over 1,000 male patients at 28 centers for the Phase III study of viprostol as a topical, prescription treatment for pattern baldness ("The Pink Sheet" Oct. 6, 1986, T&G-2). An earlier trial had tested the vasodilator in 150 patients at eight centers. At the time that Lederle expanded the clinical program, the company acknowledged the difficulty that lay ahead, noting that is was "too early" to determine whether the program would lead to "an efficacious product." After a review of the six-month data, which occurred in the first quarter of 1988, the company decided to discontinue viprostol studies "in view of the modest response rate in a limited market . . . and the cost of further studies."

[Roenigk1988-1] 1 2 Roenigk HH (1988). "New topical agents for hair growth". Clinics in Dermatology. 6 (4): 119–121. doi:10.1016/0738-081x(88)90075-2. PMID 3214817.

[KohSinclair2026-2] 1 2 Koh WL, Sinclair R (2026). "Minoxidil". Hair Loss. Updates in Clinical Dermatology. Cham: Springer Nature Switzerland. pp. 211–221. doi:10.1007/978-3-032-24862-6_18. ISBN 978-3-032-24861-9. Topical viprostol, a PGE2 analogue, can increase human hair growth and terminal hairs, although studies regarding its efficacy are conflicting [14].

[PinkSheet1988-3] 1 2 3 The Pink Sheet (18 July 1988). "Proanagen's Diazoxide-Based Hair Growth Product Beginning Efficacy". Citeline. Insights. Retrieved 27 July 2026. Another potential minoxidil competitor was recently abandoned when American Cyanamid halted Phase III trials of viprostol due its "modest response rate . . . and the cost of further studies" ("The Pink Sheet" April 25, T&G-10). Cyanamid's Shulton subsidiary subsequently announced plans to launch a line of mass market cosmetic thinning hair products in early 1989.

[Sansing1987-4] 1 2 Sansing J (10 August 1987). "Minoxidil Falls Short as Miracle Baldness Cure". Los Angeles Times. Retrieved 27 July 2026. American Cyanamid, a large pharmaceutical firm, is testing Viprostol at several locations nationwide, including the Washington Hospital Center. Similar to Minoxidil, Viprostol is a vasodilator, expanding blood vessels and facilitating blood flow. Developed in the mid-1970s for hypertension, it was never marketed. Now, working on the same hypothesis as that of Upjohn--that increased blood supply to the scalp aids hair growth--American Cyanamid has geared up for the costly and time-consuming FDA-approved human testing. Preliminary results are expected shortly.

[PinkSheet1988b-5] The Pink Sheet (25 April 1988). "Lederle Discontinuing Viprostol Baldness Studies, Will Go Cosmetic". Citeline. Insights. Retrieved 27 July 2026. Lederle discontinuing viprostol baldness studies, will go cosmetic route to a product for hair thinning, American Cyanamid noted in an April 19 press release reporting the firm's first quarter financial results. [...] "The study included the vasodilator viprostol, a carrier lotion and a placebo, [and] the individual differences in the results were not sufficiently significant to warrant further effort on viprostol." In late 1986, Lederle enrolled over 1,000 male patients at 28 centers for the Phase III study of viprostol as a topical, prescription treatment for pattern baldness ("The Pink Sheet" Oct. 6, 1986, T&G-2). An earlier trial had tested the vasodilator in 150 patients at eight centers. At the time that Lederle expanded the clinical program, the company acknowledged the difficulty that lay ahead, noting that is was "too early" to determine whether the program would lead to "an efficacious product." After a review of the six-month data, which occurred in the first quarter of 1988, the company decided to discontinue viprostol studies "in view of the modest response rate in a limited market . . . and the cost of further studies."

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See also

References