Since 1939, hormone therapy using pellets has been documented in hundreds of medical-journal articles worldwide. Here is just a fraction of those studies:

1. Anderson CHM, Rain SK Forsling ML, et al: Oestrogen replacement after oophorectomy: comparison of patches and implants. Br Med J 1992;305:90-91.
2. Asch RH, Greenblatt RB, Mahesh VB: Pure crystalline estradiol pellet implantation for contraception. Int J Fertil 1978;23:100-105.
3. Barlow DH, Abdalla HI, Roberts ADG, et al: Long-term hormone implant therapy hormonal and clinical effects. Obstet Gynecol 1986;67:321-325.
4. Bennett HG Jr, Biskind G, Mark J: Subcutaneous implantation of compressed crystalline estradiol pellets in the treatment of menopausal cases. Am J Obstet Gynecol 1940;39:504.
5. Bewley S, Bewley T: 25mg oestradiol implants - the dosage of first choice for subcutaneous oestrogen replacement therapy. Br J Obstet Gynaecol 1993;100:397.
6. Bonduelle M, McEwan HP: Monitoring oestradiol implantation. Lancet: 1987;2:1404-1405.
7. Brincat M, Magos A, Studd JWW, et al: Subcutaneous hormone implants for the control of climacteric symptoms. Lancet 1984;1:16-18.
8. Brook JG, Aviram M, Oettinger M, et al: The effect of oestrogen implants on high density lipoprotein and its subfractions in women in their premature menopause. Maturitis 1982;4:257-265.
9. Brown ML, Lucentre ER, Alesbury JM, et al: Treatment of the surgical menopause with estradiol pellets at the time of operation. Am J Obstet Gynaecol 1951;61:200-201.
10. Bryner JR, Greenblatt RB, Ellegoode JO, et al: Serum levels of estrone and estradiol after implantation of estradiol pellets. So Med J 1979;72:711.
11. Burger HG, Hailes J, Menclaus M, et al: The management of persistent symptoms with estradiol-testosterone implants: clinical, lipid and hormone results. Maturitas1984;6:351-358.
12. Campbell s, Whitehead MI: Potency and hepatocellular effects of oestrogen after oral percutaneous and subcutaneous administration. In Controversial Climacteric, ed by PA van Keep, WH Utian, A Vermeneulen. Lancaster, UK MTP Press 1988, pp103-125.
13. Cardozo LD, Gibb DMF, Studd JWW, et al.: The use of hormone implants for climacteric symptoms. Am J Obstet Gynecol1984;148:336-337.
14. Cardozo L, Gibb DMF, Tuck SM, et al: The effects of subcutaneous hormone implants during the climacteric. Maturitas1984;5:177.
15. Crook D, Montgomery JC, Godsland IF, et al: Lipid and carbohydrate metabolism in premenopausal women given subdermal estradiol implants. Horm Metab Res 1991;23:174.
16. Davis SR, McCloud B, Strauss BJG, et al.: Testosterone enhances estradiol effects on postmenopausal bone density and sexuality. Maturitas1995;21:227.
17. Deansley R, Parkes AS: Further experiments on administration of hormones by subcutaneous implantation of tablets. Lancet1939;2:606-608.
18. Delaplaine RW, Bottomy JR, Blatt M, et al: Effective control of surgical menopause by estradiol pellet implantation at the time of surgery. Surg Gynecol Obstet 1952;94:323-333.
19. Emmes CW: Rate of absorption of androgens and estrogens in free esterified form from subcutaneously implanted tablets. Endocrinol 1941;28:633-642.
20. Farish E, FletcherCD, Hart DM, et al: The effects of hormone implants on serum lipoproteins and steroid hormones in bilaterally oophorectomised women. Acta Endocrinol 1984;106:116-120.
21. Fletcher CD, Farish E, Hart Dm, et al: Long-term hormone implant therapy - effects on lipoproteins and steroid levels in postmenopausal women. Acta Endocrinol 1986;111:419-423.
22. Ganger K, Fraser D, Whitehead MI, et al: Oestrogen deficiency and oestradiol implant. Br Med J 1989;299:1279-1280.
23. Garnett TJ, Savvas, M, Studd JWW: Reversal of bone loss with percutaneous oestrogens. In HRT and Osteoporosis, ed by JO Drife, Studd JWW. London, Springer-Verlag, 1990, pp295-314.
24. Garnett T, Studd J, Watson N, et al.; A cross-sectional study of the effects of long-tem percutaneous hormone replacement therapy in bone density. Obstet Gynecol 1991;78:1002.
25. Geist SH, Walter RI, Salmon UJ: Prophylactic implantation of oestrogens following surgical and radium castration. J Mount Sinai Hosp 1941;8:543-546.
26. Ginsberg J, Hardiman P, Oestrogen deficiency and oestradiol implants. Br Med J 1989;299:1031.
27. Greenblatt RB: Testosterone propionate pellet implantation in gynecic disorders. JAMA 1943;121:11.
28. Greenblatt RB: The use of androgens in the menopause and other gynecic disorders. Obstet Gynecol Clin N Am 1987;14:251-268.
29. Greenblatt RB, Asch RH, Mahesh VB, et al: Implantation of pure crystalline estradiol for conception control. Am J Obstet Gynecol 1977;127:520-524.
30. Greenblatt RB, Bryner JR: Estradiol pellet implantation in the management of menopause; J Reprod  Med 1977;18:307-315.
31. Greenblatt RB, Hair LZ: Testosterone propionate pellet absorption in the female. J Clin Endocrinol Metab 1942;2:315-317.
32. Greenblatt RB, Suran RR: Indications for hormonal pellets in the therapy of endocrine and gynecic disorders. Am J Obstet Gynecol 1949;57:294-301.
33. Greenblatt RB, Teran AZ: Sexual dysfunction in women: Does Testosterone help? Contemp Obstet Gynecol 1986;28:129-135.
34. Guirgis RR; Oestradiol implants; what dose, how often? Lancet 1987;2:856.
35. Harriet C, Anderson M, Raju SK, et al: Oestrogen replacement after oophorectomy comparison of patches and pellets. Br Med J 1992;305:90-91.
36. Holland EFN, Leather AT, Studd JWW: The effect of 25 mg percutaneous estradiol implants on the bone mass of postmenopausal women. Obstet Gynecol 1994;83:43-46.
37. Holland EFN, Studd JWW, Mansell JP et al.: Changes in collagen composition and cross-link in bone and skin of osteoporotic postmenopausal women treated with percutaneous estradiol implants. Obstet Gynecol 1944;83:180-183.
38. Hunter DJS, Akande EO, Carr P, et al: The clinical and endocrinological effect of oestradiol implants at the time of hysterectomy and bilateral salpingo-oophorectomy. J Obstet Gynaecol Br Com 1973;80:827-833.
39. Hunter DJS, Julier D, Franklin M, et al:Plasma levels of oestrogen, luteinizing hormone,and follicle stimulating hormone following castration and estradiol implant. Obstet Gynecol 1977;49:180.
40. Jarolim C,Bernard LI, Straus Ah: Estrogen substitution therapy with pellet implantation. Am J Obstet Gynecol 1966;170-177.
41. Kapetanakis E, Dmowski P, Auletta F, et al: Endocrine and clinical effects of estradiol and testosterone pellets used in long-term replacement therapy. Int Gynaecol Obstet 1982;20:387-399.
42. Kupperman HS, Delaplaine RW, Bottomy Jr: Effective control of surgical menopause by estradiol implantation at the time of oophorectomy and total hysterectomy. J Clin Endocrinol Metab 1951;11:788.
43. Lipshutz A,Vargas L,: Absorption of estradiol and its esters from subcutaneously  implanted tablets in guinea pig. Pro Soc Exper Biol Med 1941;48:464-467.
44. Lobo RA, March CM, Goebelsmann U, et al: Subdermal estradiol pellets following hysterectomy and oophorectomy. Am Obstet Gynecol 1980;138:714-719.
45. Loeser AA: Subcutaneous implantation of female and male hormone in tablet form in women. Br Med J 1940;1:479.
46. Magos Al, Brincat M, O’Dowd T, et al: Endometrial and menstrual response to subcutaneous estradiol and testosterone implants and continuous oral progestogen therapy in postmenopausal women. Maturitias 1985;7:297.
47. Magos Al, Brincat M, Studd JWW: Treatment of the premenstrual syndrome by subcutaneous oestradiol implants and oral norethisterone: placebo controlled study. Br Med J 1986;292:1629-1633.
48. Magos Al, Collins WP, Studd JWW: Management of the premenstrual syndrome by subcutaneous implants of oestradiol. J Psychosom Obstet Gynecol 1984;3:93-99.
49. Magos Al, Zilkha KJ, Studd JWW: Treatment of menstrual migraine by oestradiol implants. J Neurol Neurosurg Psychiat 1983;46:1044-1046.
50. Mishell DR: A clinical study of estrogenic therapy with pellet implantation. Am J Obstet Gynecol 1941;41:1009-1017.
51. Montgomery JC, Appleby L, Brincat M, et al.: Effect of estrogen and testosterone implants on psychological disorders of the climacteria. Lancet 1987;1:297-299.
52. Nagamani M, Lin TJ, McDonough PG, et al.: Clinical and endocrine studies in menopausal women after estradiol pellet implantation. Obstet Gynecol 1977;50:541-547.
53. Nezhat C, Karpas AC, Greenblatt RB, et al: Estradiol implants for conception control. Am J Obstet Gynecol 1980;138;1151-1156.
54. Notelovitz M, Johnston M, Smith S, et al: Metabolic and hormonal effects of 25 mg and 50 mg17-b estradiol implants in surgically menopausal women. Obstet Gynecol 1987;70:749-754.
55. Okie V: Treatment of menopausal by estradiol pellet implantation. NY State J Med 1949;49:1175-1176.
56. Owen EJ, Siddle NC, McGarrigle HT, et al: 25mg oestradiol implants - the dosage of first choice for subcutaneous oestrogen replacement therapy. Br J Obstet Gynecol 1992;99:671-675.
57. Perloff WH: Treatment of oestrogen deficiency with estradiol pellets. J Clin Endocrinol Metab 1950;10:447-454.
58. Ralston SH, Fogelman I, LeggateJ, et al: Effect of subdermal oestrogen and oestrogen/testosterone implants on calcium and phosphorous homeostasis after oophorectomy. Maturitas 1984;6:341.
59. Salmon UJ, Geist SH, Walter RI: Inhibitory effect of implanted estrogenic crystals upon postmenopausal and castration hypophysis of women. Proced Soc Exper Biol Med 1940;43:424-426.
60. Salmon UJ, Geist SH, Walter RI: Treatment of the menopause: Evaluation of estrogen implantation. JAMA 1941;117:1843-1849.
61. Salmon UJ, Walter RI, Geist SH: Prolonged therapeutic effect of subcutaneously implanted crystals of ovarian hormone in women. Science 1939;90:162-163.
62. Savvas M, Studd JWW, Fogelman I, et al: Skeletal effects of oral estrogen compared with subcutaneous oestrogen and testosterone in postmenopausal women. Br Med J 1988;297:331-333.
63. Schleyer-Saunders E: Social and gerontological problems of the menopause: hormone implants. In The Menopausal Syndrome, ed by Greenblatt RB, Mahesh VB, McDonough PG. New York Medcom Press 1974, pp. 88-94.
64. Sharf MS, Oettinger M, Lanir A, et al: Lipid and lipoprotein levels following pure estradiol implantation in post-menopausal women. Gynecol Obstet Invest 1985;19:207-212.
65. Soule SD: Treatment of the postsurgical menopause by implantation of estradiol pellets. J Int Col Surg 1951;16:622-630.
66. Staland B: Treatment of menopausal estrogen deficiency symptoms in hysterectomized women by means of 17-b estradiol pellet implants. Acta Obstet Gynaecol Scand 1978;57:281-285.
67. Stanczyk FZ, Shoupe D, Nunez V, et al: A randomized comparison of non-oral estradiol delivery in postmenopausal women. Am J Obstet Gynecol 1988;159:1540-1546.
68. Studd JWW: Hormonal implants in the climacteric syndrome. In The Management of the Menopause and Postmenopause years, ed by S Campbell. London, MTP Press 1976, pp. 383-385.
69. Studd JWW, Cardozo LD, Gibb DMF, et al: Hormone implants in women following hysterectomy and bilateral salpingoophorectomy. In Climacteric - An Update, ed by H & B van Herendael, FE Riphagen,et al. Boston, MTP Press, Ltd, 1983; pp149-155.
70. Studd JWW, Collins WP, Newton JR, et al: Oestradiol and testosterone implants in the treatment of psychosexual problems of postmenopausal women. Br J Obstet Gynecol 1977;84:314-315.
71. Studd J, Henderson A, Garnett T, et al: Symptoms of oestrogen deficiency in women with oestradiol implants. Br Med J 1989;299:1400-1401.
72. Studd J, Magos A: Hormone pellet implantation for the menopause and premenstrual syndrome. Obstet Gynecol Clin N Am 1987;14:229-249.
73. Studd JWW, Savvas M, Fogelman I, et al: The relationship between plasma oestradiol and the increase in bone density in postmenopausal women following subcutaneous hormone implants. Am J Obstet Gynecol 1990;163:1474-1479.
74. Studd JWW, Savvas M, Watson NR, et al: Monitoring oestradiol implantation.  Lancet 1987;2:1404-1405.
75. Swyer, GIM: Symptoms of oestrogen deficiency in women with oestradiol implants.  Br Med J 1989;299:854.
76. Teran AZ, Gambrell RD Jr: androgens in clinical practice. In Androgens in the Menopause, ed by L Speroff. New York, McGraw Hill, 1988, pp14-22.
77. Thom MH, Collins WP, Studd JWW: Hormonal profiles in postmenopausal women after therapy with subcutaneous implants. Br J Obstet Gynaecol 1981;88:426-433.
78. Thom MH, Studd JWW: Oestrogen and testosterone implant therapy. In Oestrogen and the Menopause, ed Whitehead MJ, Campbell S, Queensboro, Kent, Abbott Laboratories, Ltd, 1978, pp 85-88.
79. Thom MH, Studd JWW: Procedures in practice: Hormone Implantation, Br Med J 1980;1:848-850.
80. Tobias JH, Chambers TJ: Symptoms of oestrogen deficiency in women with oestradiol implants. Br Med J 1989;299:854.
81. Twombly GH, Millen Rs: The implantation of solid pellets of estrogens in the treatment of menopausal symptoms. Surg Gynecol Obstet 1941;72:605-610.
82. Walter RI, Geist SH, Salmon UJ: Absorption rates and biologic effects of pellets of a-estradiol and a-estradiol benzoate in women. Proc Soc Exper Biol Med 1940;44:314-318.
83. Wardle P, Fox R: Symptoms of oestrogen deficiency in women with oestradiol implants Br Med J 1989;299.
84. Watson NR, Studd JWW, Savvas M, et al.: The long term effects of estradiol implant therapy for treatment of pre-menopausal syndrome. Gynecol Endocrinol 1990;4:99-107.