Porcine FSH
The pig pituitary FSH used to make donor cows and ewes release many eggs for embryo transfer, what the trials show, and why it has no place in human medicine
Porcine FSH is follicle-stimulating hormone purified from pig pituitary glands, with a little luteinizing hormone left in. Embryo-transfer practitioners inject it into donor cows, heifers and ewes so that many follicles grow at once and several eggs ovulate, a process called superovulation. Because the hormone clears quickly, the classic schedule is two injections a day for four days, and much of the research has tried to replace that with one or two injections. It is approved in the US and the UK only as a veterinary medicine for cattle. No study giving it to people was found.
No established human dose Details ↓
Recommended Dosing
No established human dose
No human dose exists for porcine FSH. It is approved only as a veterinary medicine, its US label says it is not for use in humans, and every study read here was done in cattle, sheep, goats, pigs, horses, monkeys or rats with amounts chosen for those animals.
What is it?
Follicle-stimulating hormone is the pituitary hormone that recruits and grows ovarian follicles. Porcine FSH is that hormone taken from the pituitary glands of slaughtered pigs and purified. Chemists isolated and characterised it in the 1970s and early 1980s, separating its two subunits and showing that neither works alone but that recombined they recover part of the activity. Commercial preparations keep only a small amount of luteinizing hormone: Folltropin was introduced in 1990 as an FSH preparation with reduced LH activity, and in beef heifers it matched the older product it replaced.
Its use is embryo transfer in livestock. A genetically valuable cow normally releases one egg per cycle. Given FSH during the middle of the cycle, she grows many follicles at once; after a prostaglandin injection brings her into heat and she is inseminated, several embryos form, are flushed out about a week later and are transferred to recipient cows. The same approach is used in ewes and goats, and to grow follicles before oocytes are collected for laboratory embryo production.
Porcine FSH lasts only a short time in the blood, so the standard schedule is two intramuscular injections a day for about four days, in decreasing amounts. That is labour-intensive and stressful for the animals, and much of the research in this entry tests alternatives: a single injection under the skin behind the shoulder, which works in well-conditioned beef cows but less reliably in thin cows or Holsteins; a single or split injection in a slow-release hyaluronan gel; and, recently, comparison with a long-acting recombinant FSH that needs only one dose.
The trials also show the limits. Responses vary widely between animals, partly with the animal's own FSH levels. The amount matters in ewes, where too little gave poor embryo yields. Goats treated repeatedly made antibodies against the pig hormone and stopped responding, a known risk of giving one species' hormone to another. In mares porcine FSH works poorly. In one dairy-cow study a single dose given at the wrong time in a breeding protocol disrupted ovulation.
Porcine FSH is approved in the US as Folltropin for superovulation of beef and dairy heifers and cows, and authorised in the UK as a veterinary medicine. Its US label says it is not for use in humans and warns that accidental self-injection may affect women and an unborn child. Human fertility medicine uses human FSH preparations, covered under follitropin alfa, urofollitropin and menotropin. No study of porcine FSH given to people was found in PubMed searches, and the veterinary amounts are not human doses.
Mechanism of Action
Porcine FSH binds the FSH receptor on the granulosa cells of ovarian follicles, so that many follicles grow at once instead of one; ovulation then needs an LH signal, from the animal's own surge or from GnRH or hCG.
Follicle recruitment
Raising FSH above the animal's own level during a follicular wave rescues many follicles that would otherwise regress.
Short-lived in the blood
FSH levels fall back toward baseline within about one and a half to two and a half days after an injection, which is why repeated or slow-release dosing is used.
The LH balance
Commercial preparations keep LH low; gilts needed more LH than FSH alone supplies to reach heat and ovulate.
Antibodies
As a hormone from another species, repeated use can trigger antibodies that blunt the response, as in goats.
Published Research
These studies were read from their PubMed abstracts on October 29, 2026. They are trials and analyses in cattle, sheep, goats, pigs, horses and monkeys, two studies in rats, and the biochemistry that first purified the hormone. Each card names its species; none was carried out in people, and the amounts in the cards are veterinary amounts, not human doses.
Review: replacing twice-daily injections in cattle
A single injection under the skin worked but depended on body condition and site, with the fat pad behind the shoulder best; in Holsteins a 75/25 split two days apart was more reliable. A single intramuscular injection in a 2% hyaluronan gel matched the four-day schedule, and in 0.5% gel it worked before ovum pick-up. FSH had to stay above baseline for about 72 hours for superovulation.
Folltropin against another FSH product in 3,990 dairy flushes
A Finnish retrospective study of 3,990 commercial superovulations over 16 years found the same number of transferable embryos with Folltropin (7.0) and with another pituitary FSH product (7.1), with similar embryo quality and similar pregnancy rates after transfer; the other product gave more unfertilised eggs.
One injection under the skin in beef cows
A single subcutaneous injection of Folltropin-V gave the same superovulatory response as twice-daily intramuscular injections for four days. Placement behind the shoulder was more reliable than the neck in thin cows, and higher amounts left more unovulated follicles without adding embryos.
Finding the dose of a low-LH preparation in heifers
In beef heifers, Folltropin, a preparation with reduced LH, matched the older FSH-P product across a range of doses; the lowest dose gave fewer corpora lutea and embryos, and doses above twice the optimum did not harm embryo quality.
A single intramuscular injection in a slow-release gel
In beef cows, one intramuscular injection of Folltropin-V in a 2% hyaluronan slow-release solution gave as many corpora lutea and transferable embryos as the four-day twice-daily schedule; the same injection in a half-strength gel produced fewer embryos.
Two injections 48 hours apart
Splitting the total Folltropin-V dose into two intramuscular injections two days apart, in thinner hyaluronan solutions that are easier to mix, gave the same numbers of transferable embryos in beef cows as the twice-daily four-day protocol, in a crossover design.
One injection before ovum pick-up in Holsteins
In Holstein heifers a single intramuscular injection of porcine FSH in 0.5% hyaluronan produced a blood FSH profile similar to four injections. In 90 non-lactating cows, any FSH treatment raised oocyte and blastocyst yields over untreated donors, and the lower single dose did better than the higher one; pregnancy rates after transfer were similar.
Single subcutaneous injection in Japanese Black cows
In Japanese Black cows, one subcutaneous injection of porcine FSH in the neck, at either of two doses and in either 10 or 50 mL of saline, gave as many corpora lutea, embryos and transferable embryos as six intramuscular injections over three days.
Eight pituitary doses against one recombinant dose
In 569 commercial superovulations, eight injections of porcine FSH and a single injection of a long-acting recombinant FSH yielded similar numbers of recovered structures and transferable embryos; recombinant FSH gave more unfertilised eggs and pituitary FSH more degenerated embryos.
Porcine FSH against hMG in Japanese Black cattle
In 30 superovulations, cattle given human menopausal gonadotrophin tended to yield more ova and a higher share of excellent embryos than those given porcine FSH, with a faster early rise in oestradiol and higher progesterone after heat, differences the authors link to embryo quality.
Given at the wrong time, it disrupted ovulation
Lactating dairy cows given Folltropin-V at the start of induced luteolysis in a timed-insemination protocol had lower oestradiol, and four of 14 failed to ovulate after GnRH or hCG, some with a blunted LH surge; the authors judged the treatment unsuitable for that use.
Dose decides the response in Lacaune ewes
In 24 lactating ewes, the higher of two porcine FSH doses gave more ewes in heat, about 11.6 versus 2.6 corpora lutea, and 6.9 versus 1.0 viable embryos with better recovery; the lower dose was insufficient.
Two doses compared in Santa Inês ewes
In 36 ewes both doses of porcine FSH produced an efficient superovulatory response, but the higher one recruited more medium and large follicles, lengthened heat and yielded more freezable embryos (6.5 versus 2.3).
Smaller doses with eCG in ewes
When combined with eCG at the start of treatment, the lowest of three porcine FSH doses gave as many viable embryos in Santa Inês ewes as the traditional dose, though with more unfertilised eggs; the middle dose did worst.
One injection in a polymer carrier in ewes
A single intramuscular injection of porcine FSH dissolved in polyvinylpyrrolidone, given 24 hours before sponge removal, matched the ovulation rate and embryo yield of multiple injections in Leccese ewes, but most other single-injection versions failed to induce superovulation.
The ewe's own FSH explains part of the variation
In 18 anoestrous ewes superovulated with Folltropin-V, blood levels of the injected pig FSH did not differ between groups, but the ewes' own FSH levels at several times correlated with the number of corpora lutea and embryos.
Repeated treatment raises antibodies in goats
Goats given porcine FSH every six weeks for seven months made antibodies to it after the first injection, rising with each booster; antibody levels correlated closely with a falling superovulatory response, explaining refractoriness to repeated treatment.
Prepubertal gilts need more LH than FSH alone provides
In prepubertal gilts, Folltropin alone or with a little LH grew medium follicles but did not sustain them or bring on heat; adding more LH or hCG gave heat in over 70%, ovulation in all and more than 30 corpora lutea, with temporary follicular cysts.
Works poorly in mares
In 22 mares in early spring transition, equine FSH brought all 11 to pre-ovulatory follicles and 8 to ovulation, while porcine FSH did so in 5 and 4 of 11; the authors could not recommend the porcine regimen.
No better in mares prone to multiple ovulations
In crossbred and Brazilian Warmblood mares, porcine FSH given after follicle ablation or at wave emergence did not enhance follicle growth, ovulation or embryo collection over controls, and did less than an equine pituitary extract.
Ovarian stimulation in macaque monkeys
Nine rhesus monkeys given twice-daily intramuscular Folltropin-V followed by hCG yielded a mean of 20 eggs each; 71% were mature, 92% of those fertilised in vitro and 48% became blastocysts, results the authors found similar to human or equine gonadotropins at lower cost.
Clearance differs with the pig breed it came from
Infused into hypophysectomised rats, FSH from pituitaries of Chinese Meishan boars left the blood more slowly than FSH from crossbred Western pigs, suggesting structural differences between breeds with similar receptor activation.
Purifying the hormone
Methods were developed to isolate highly purified FSH from pig pituitaries, with almost no LH by immunoassay. The pure hormone was rich in aspartic and glutamic acids and contained about 6% sialic acid, and a specific radioimmunoassay was developed.
Its two subunits
The alpha and beta subunits of porcine FSH were separated to purity. Alone each had under 1% of the hormone's activity, but recombined they regained at least 23%; the alpha subunit carried far more sialic acid than the beta.
No Established Human Dose
No human dose exists for porcine FSH. It is approved only as a veterinary medicine, its US label says it is not for use in humans, and every study read here was done in cattle, sheep, goats, pigs, horses, monkeys or rats with amounts chosen for those animals. No study giving porcine FSH to people was found, so the veterinary amounts are not shown as doses and none applies to a person.
What this rests on: PMID 29208313, PMID 16727835, PMID 16727010.
Educational information, not medical advice. The doses on this page come from approved labels, published studies and, where no study exists, amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
What a Buyer Needs to Know
What is sold, how it is mixed, stored and taken, and what is known about its safety, quality and legal status. Each part names its source. Where we have none, it says unknown.
What is sold
No product is approved for people. The approved veterinary product, as its US veterinary label describes it:
- Folltropin (follicle stimulating hormone (porcine ) injection) (veterinary): FOLLTROPIN ® DUAL PACK contains two 20 mL vials each containing 700 IU FSH as a lyophilized powder.
Source: Folltropin (follicle stimulating hormone (porcine ) injection) veterinary label, How Supplied (DailyMed version 5, effective July 7, 2026).
Mixing a vial: a worked example
Unknown: no human dose of Porcine FSH has been established (see No Established Human Dose below), so there is no amount to work out. The reconstitution calculator does the arithmetic for any vial, water and dose.
Storage before and after mixing
No product of Porcine FSH is approved for people. The US veterinary label of the approved animal product says how it is stored:
Folltropin (follicle stimulating hormone (porcine ) injection) (veterinary): “Freeze-dried powder vials: Do not store above 25°C (77°F).” “Reconstituted solution: Store under refrigeration 2-8°C (36-46°F).” “Keep the vials in the outer carton in order to protect from light.” “Shelf life following reconstitution according to directions: 4 days” “Do not freeze after reconstitution.”
These describe the veterinary product in its own container, not a vial sold for people. The mixing guide sets out the general rules for a mixed vial, with their sources.
Source: Folltropin (follicle stimulating hormone (porcine ) injection) veterinary label, storage section (DailyMed version 5, effective July 7, 2026).
How it is taken
Unknown: with no established human dose, there is no established way of taking Porcine FSH. What the human studies gave and how is set out under No Established Human Dose.
What to expect, and when
Unknown: no cited half-life and no label or trial duration on this page says how long Porcine FSH lasts or how long it was given. Results reported in the studies are under Published Research.
Side effects, and when to stop or get help
From the Side Effects section: Antibodies and a falling response with repeated treatment in goats (PMID 16727010); Ovulation failure when given at the start of luteolysis in a timed-insemination protocol in dairy cows (PMID 23534994); Temporary follicular cysts and poorly formed corpora lutea in gilts given FSH with LH (PMID 22683028); Unovulated follicles at higher single-injection amounts in beef cows (PMID 16727601); The US label notes reports of cystic ovaries, not confirmed in controlled studies, and possible trim loss at the injection site at slaughter (veterinary label). Full list and cautions ↓
When to stop or get help: unknown; no label or trial on file sets rules for stopping Porcine FSH. Treat a severe or unexpected reaction as a reason to stop and see a doctor.
Source: the Side Effects section below (“Reported in animals; no human safety data were found”).
Interactions
Unknown: a PubMed search for human interaction studies of Porcine FSH (reviewed 2026-10-28) found none. Unknown is not the same as safe to combine.
Every peptide's record, with its source: the interaction matrix.
Checking what you bought
Unknown: no published independent test of Porcine FSH products is in our lab-results database yet, so how products sold under this name measure up is not known.
To read a certificate of analysis, paste it into the COA decoder. Trust & Verification explains what independent testing can and cannot show.
Legal status
US: Veterinary Only (Approved only for animals). Sport: Prohibited (S0 catch-all).
Country by country ↓ · Regulatory tracker
Source: this entry's approval status and the WADA Prohibited List, as in Legal Status below.
Side Effects & Contraindications
Reported Side Effects
Reported in animals; no human safety data were found.
Contraindications & Cautions
For people, the main point is that porcine FSH is not a human medicine.
Legal Status
Porcine FSH is a veterinary medicine. No human approval was found.
Frequently Asked Questions
?What is porcine FSH?
Follicle-stimulating hormone purified from pig pituitary glands, with a small amount of LH. It is sold for animals as Folltropin.
?What is it used for?
Superovulation of donor cows, heifers and ewes for embryo transfer, and stimulating follicles before oocytes are collected for laboratory embryo production.
?Is porcine FSH used in human fertility treatment?
No study giving it to people was found, and its US label says it is not for use in humans. Human fertility medicine uses human FSH: urinary, as in urofollitropin and menotropin, or recombinant, as in follitropin alfa.
?Why is it injected so often?
It clears from the blood within a day or two, so the classic protocol uses two injections a day for four days. Single injections under the skin or in slow-release gels have matched that in many cattle trials.
?Does it work in every species?
It works in cattle, sheep, goats and macaque monkeys, but poorly in mares, and goats treated repeatedly made antibodies and stopped responding.
?Is it risky for the people who handle it?
The label warns that accidental self-injection may have effects in women and, in pregnancy, on the unborn child, and advises seeking medical attention.
References
- [fda-pi] Folltropin (porcine pituitary-derived follicle stimulating hormone), US FDA-approved veterinary label (description, effectiveness and dosage; DailyMed set 461175db, version 5, effective July 7, 2026; read October 28, 2026).
- [other] US FDA Center for Veterinary Medicine, Approved Animal Drug Products (Green Book), Section 2 active-ingredient list downloaded from Animal Drugs @ FDA, read October 28, 2026: NADA 141-431, Folltropin, active ingredient porcine pituitary-derived follicle stimulating hormone. https://animaldrugsatfda.fda.gov/adafda/views/#/search
- [other] UK Veterinary Medicines Directorate, Product Information Database, currently authorised products searched by active substance, read October 28, 2026: Folltropin 700 IU powder and solvent for solution for injection, VM 08007/5005, active substance follicle stimulating hormone (porcine), target species cattle. https://www.vmd.defra.gov.uk/ProductInformationDatabase/
- [review] Bó GA, et al. "Pursuit of a method for single administration of pFSH for superstimulation in cattle: What we have learned." Theriogenology, 2018;112:26-33. PMID: 29208313.
- [pubmed] Mikkola M, et al. "Embryo yield in dairy cattle after superovulation with Folltropin or Pluset." Theriogenology, 2017;88:84-88. PMID: 27865416.
- [pubmed] Bo GA, et al. "Superovulatory response to a single subcutaneous injection of Folltropin-V in beef cattle." Theriogenology, 1994;42(6):963-75. PMID: 16727601.
- [pubmed] Gonzalez A, et al. "Superovulation of beef heifers with Folltropin: A new FSH preparation containing reduced LH activity." Theriogenology, 1990;33(2):519-29. PMID: 16726748.
- [pubmed] Tríbulo A, et al. "Superstimulation of ovarian follicular development in beef cattle with a single intramuscular injection of Folltropin-V." Anim Reprod Sci, 2011;129(1-2):7-13. PMID: 22115521.
- [pubmed] Tríbulo A, et al. "Superovulation of beef cattle with a split-single intramuscular administration of Folltropin-V in two concentrations of hyaluronan." Theriogenology, 2012;77(8):1679-85. PMID: 22401834.
- [pubmed] Vieira LM, et al. "Efficacy of a single intramuscular injection of porcine FSH in hyaluronan prior to ovum pick-up in Holstein cattle." Theriogenology, 2016;85(5):877-886. PMID: 26639640.
- [pubmed] Hiraizumi S, et al. "Superovulatory response in Japanese Black cows receiving a single subcutaneous porcine follicle-stimulating hormone treatment or six intramuscular treatments over three days." Theriogenology, 2015;83(4):466-73. PMID: 25476823.
- [pubmed] Frata MM, et al. "Single-dose recombinant FSH as a viable alternative to multi-dose porcine FSH in commercial superovulation protocols in cows." Theriogenology, 2025;244:117498. PMID: 40403572.
- [pubmed] Sugano M, et al. "Endocrine profiles and embryo quality in Japanese black cattle superovulated with human menopausal gonadotrophin and porcine follicle stimulating hormone." Reprod Domest Anim, 2001;36(2):57-63. PMID: 11328557.
- [pubmed] Giordano JO, et al. "Ovulatory follicle dysfunction in lactating dairy cows after treatment with Folltropin-V at the onset of luteolysis." Theriogenology, 2013;79(8):1210-7. PMID: 23534994.
- [pubmed] Figueira LM, et al. "In vivo embryo production and recovery in lacaune ewes after imposing a superovulation treatment regimen is related to pFSH dose." Anim Reprod Sci, 2020;223:106625. PMID: 33075735.
- [pubmed] Ribeiro ACS, et al. "The pFSH dose affects the efficiency of in vivo embryo production in Santa Inês ewes." Anim Reprod Sci, 2024;264:107459. PMID: 38598889.
- [pubmed] Maciel GS, et al. "Follicular dynamics and in vivo embryo production in Santa Inês ewes treated with smaller doses of pFSH." Anim Reprod Sci, 2019;209:106137. PMID: 31514927.
- [pubmed] D'Alessandro AG, et al. "Superovulation in ewes by a single injection of pFSH dissolved in polyvinylpyrrolidone (PVP): effects of PVP molecular weight, concentration and schedule of treatment." Anim Reprod Sci, 2001;65(3-4):255-64. PMID: 11267805.
- [pubmed] Bartlewski PM, et al. "Systemic concentrations of endogenous and exogenous FSH in anoestrous ewes superstimulated with folltropin-V." Reprod Domest Anim, 2009;44(2):353-8. PMID: 19055560.
- [pubmed] Remy B, et al. "Are antibodies responsible for a decreased superovulatory response in goats which have been treated repeatedly with porcine follicle-stimulating hormone?." Theriogenology, 1991;36(3):389-99. PMID: 16727010.
- [pubmed] Breen SM, et al. "The impact of dose of FSH (Folltropin) containing LH (Lutropin) on follicular development, estrus and ovulation responses in prepubertal gilts." Anim Reprod Sci, 2012;132(3-4):193-200. PMID: 22683028.
- [pubmed] Raz T, et al. "Ovulation, pregnancy rate and early embryonic development in vernal transitional mares treated with equine- or porcine-FSH." Reprod Domest Anim, 2010;45(2):287-94. PMID: 19144034.
- [pubmed] Ignácio FS, et al. "Ovarian response to porcine FSH in association with ablation-induced or spontaneous follicular wave development during the estrous cycle in crossbred and Brazilian Warmblood mares." Anim Reprod Sci, 2013;137(1-2):82-7. PMID: 23332585.
- [pubmed] Schramm RD, et al. "Use of purified porcine follicle-stimulating hormone for ovarian stimulation of macaque monkeys." Theriogenology, 1996;45(4):727-32. PMID: 16727835.
- [pubmed] Macdonald GJ, et al. "Breed differences in clearance of porcine FSH in hypophysectomized rats." Anim Reprod Sci, 2007;102(3-4):328-34. PMID: 17418509.
- [pubmed] Whitley RJ, et al. "Studies on the isolation and chemical-physical properties of porcine follicle-stimulating hormone." Endocrinology, 1978;102(6):1874-86. PMID: 744055.
- [pubmed] Whitley RJ, et al. "Isolation and characterization of the subunits of porcine follicle-stimulating hormone." Endocr Res Commun, 1981;8(1):61-81. PMID: 6786858.
Sources & Citations
Every study on this page was read from its PubMed record on October 29, 2026. Approval status comes from the FDA Green Book, the DailyMed veterinary label and the UK Veterinary Medicines Directorate, read October 28, 2026. A PubMed search for pFSH, Folltropin or porcine FSH in titles and abstracts returned 460 records, none a study in people; ClinicalTrials.gov, Drugs@FDA and the EMA list returned none (October 28, 2026). Grey Peptides sells nothing and links to no vendor.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Talk to a licensed clinician about your own situation.