Nasal testosterone, buccal tablets and pellets: the evidence

Nasal testosterone is the only one of these three routes available in Canada. In the trial published in Andrology in 2016, which enrolled 306 men at 39 United States sites, 73 percent of the intent-to-treat population were in the normal range at day 90. Buccal tablets are discontinued in every market checked, and implanted pellets have never been sold in Canada.

Key takeaways

• Health Canada’s Drug Product Database, checked 14 September 2026, lists one nasal testosterone gel in marketed status, DIN 02450550. It is authorized in the United States under NDA 205488 and absent from the United Kingdom and Australian registers.
• In the nasal gel trial published in Andrology in 2016, 73 percent of the intent-to-treat population and 90 percent of the fixed-dose arm reached the normal range at day 90.
• In the matched-cohort study published in the Canadian Urological Association Journal in 2023, hematocrit fell by 0.8 percent on nasal gel over 16 weeks while rising 4.4 percent on cypionate injection and 1.7 percent on pellets.
• Buccal testosterone is discontinued everywhere. The United States product, NDA 021543, is listed as discontinued in Drugs@FDA, and it was never authorized in Canada or Australia.
• Implanted pellets are sold in only one of the four countries checked on 14 September 2026, the United States (ANDA 080911). Australia’s 100 mg implant was cancelled by its sponsor under section 30(1)(c) of the Therapeutic Goods Act, with no safety reason on record.

Who does this page apply to?

This page applies to men with confirmed low testosterone. The European Association of Urology guidelines on male hypogonadism, 2026 edition, make a strong recommendation to use a total testosterone of 12 nmol/L (3.5 ng/mL) as the diagnostic threshold, measured fasting between 07:00 and 10:00 and confirmed on two separate occasions. It does not apply to men whose testosterone is normal, and none of the studies below enrolled such men. The diagnostic steps are set out in how low testosterone is diagnosed in Canada. What testing your own case needs is a decision for your doctor or nurse practitioner.

Is nasal testosterone available in Canada?

Yes. Health Canada’s Drug Product Database, checked 14 September 2026, lists Natesto nasal gel 4.5 percent, 5.5 mg per actuation, from Acerus Biopharma, DIN 02450550, in marketed status, one of 13 marketed human testosterone drug identification numbers in Canada on that date.

The same route is authorized in the United States under NDA 205488, does not appear in the United Kingdom Electronic Medicines Compendium, and is not on the Australian Register of Therapeutic Goods. It is one of the few forms Canada has and two of those countries do not, as set out in testosterone products compared across four countries.

What did the nasal testosterone trials find?

The main efficacy evidence is a 306-man study published in Andrology in 2016, run at 39 United States sites. At day 90, 73 percent of the intent-to-treat population were in the normal range, and 90 percent of the fixed-dose arm were. Discontinuation for adverse events occurred in 2.1 percent of men dosing twice daily and 3.7 percent of men dosing three times daily. The abstract states that there is “no risk of secondary transference,” the practical contrast with gels.

That trial has one limitation the authors state directly: it “lacked a placebo or an active comparator control.” It shows that men reached the normal range, not that the route outperformed anything else.

An analysis published in the Journal of the Endocrine Society in 2019 asked whether the starting level changed the result. Maximum concentration was nearly identical across baseline strata, luteinizing hormone stayed in the normal range, and men with severe deficiency improved much like the rest.

Does nasal testosterone affect fertility hormones?

A six-month single-arm study published in The Journal of Urology in 2020 enrolled 60 men aged 18 to 55 using the nasal gel three times daily. At six months, 90.9 percent were above 300 ng/dL. Follicle-stimulating hormone stayed in the normal range in 81.8 percent of men and luteinizing hormone in 72.7 percent. Total motile sperm count stayed above 5 million in 88.4 percent of men at three months and 93.9 percent at six months.

The authors put their own limit on that result: “Long-term studies beyond 6 months are needed before we can safely prescribe nasal testosterone gel for men interested in fertility.” Attrition was substantial, with 44 and 33 of the 60 enrolled men evaluated at three and six months, and there was no comparison group.

Do seasonal allergies change how nasal testosterone is absorbed?

A study published in the Canadian Urological Association Journal in 2018 found no difference in the rate or extent of absorption as a function of allergy symptoms. It did report one difference: pre-dose mean testosterone was 21 to 25 percent lower when subjects were symptomatic.

Why is nasal the one route linked with a fall in hematocrit?

Because of a single Canadian study. The matched-cohort analysis published in the Canadian Urological Association Journal in 2023 compared 78 men matched for age, body mass index and sleep apnea over 16 weeks across three routes. Testosterone rose on all three: cypionate injection from 240.8 to 585.5 ng/dL, nasal gel from 230.3 to 493.5 ng/dL, and pellets from 210.8 to 360.5 ng/dL, all with p less than 0.001.

Hematocrit moved in different directions. It rose 4.4 percent on cypionate and 1.7 percent on pellets, and fell by 0.8 percent on nasal gel. That is the only study to place the nasal route in a direct hematocrit comparison, and it is small, retrospective and not randomized. The wider comparison is covered in testosterone and hematocrit by formulation.

What was buccal testosterone, and why is it no longer sold?

Buccal testosterone was a tablet held against the gum above an incisor, used twice daily. It is discontinued in every market checked on 14 September 2026. The United States product, Striant, NDA 021543, is listed as discontinued in Drugs@FDA, it is absent from the United Kingdom Electronic Medicines Compendium, and it was never authorized in Canada or Australia.

The pharmacokinetic evidence was reasonable for its time. A study published in the European Journal of Endocrinology in 2004 followed 12 men using the buccal system twice daily for seven days: the peak was 26.6 plus or minus 5.8 nmol/L at 4.8 hours, levels stayed in the eugonadal range, and six of the 12 men preferred it to their previous therapy. A review published in the International Journal of Clinical Practice in 2004 reported that 87 to 97 percent of phase III patients achieved 24-hour average concentrations in the normal range, with a 3.5 percent discontinuation rate for adverse events.

The tolerability data explain the commercial outcome. A paper published in BJU International in 2012, covering up to two years of use, reported gum-related disorders in 5.6 to 16.3 percent of users and taste perversion in 3.0 to 4.1 percent, while 90 percent rated twice-daily dosing acceptable. Its authors were affiliated with the company that made the product, and the data came from previously unpublished studies.

The one detail worth keeping from the buccal record

In a case published in The Journal of Sexual Medicine in 2010, a 10-month-old boy developed precocious puberty from contact with his father’s topical testosterone, and the symptoms receded once the father switched from the topical product to a buccal one. That observation illustrates why the route determines transfer risk. The gel transfer evidence is set out in testosterone gels and creams and the transfer risk.

Are testosterone pellets available in Canada?

No. Implanted testosterone pellets have never been authorized in Canada and do not appear in the Drug Product Database at any status. Among the four countries checked on 14 September 2026 they are sold only in the United States, as a 75 mg pellet under ANDA 080911. Australia’s 100 mg implant was cancelled by its sponsor under section 30(1)(c) of the Therapeutic Goods Act, a sponsor request, and no safety reason for it appears on the public record.

What did the pellet studies find?

Pellets are inserted under the skin in a minor office procedure and release testosterone over months. A multi-institutional observational study published in The Journal of Sexual Medicine in 2012 covered 380 men and 702 insertions across six academic centres. Six to ten or more pellets, described by the authors as 450 to 750 mg or more, raised total testosterone into the therapeutic range at one month and sustained levels above 300 ng/dL for four to six months, and ten to twelve pellets gave higher and longer maintenance. Four extrusions and three hematomas were reported early.

A study published in the Journal of Andrology in 2012, covering 273 patients and 501 insertions, found that men with a body mass index at or above 25 reached lower peaks with slower decay, while both groups came back down to 300 ng/dL at about 100 days. The authors recommended reimplantation at 100 to 120 days.

A prospective study published in The Journal of Sexual Medicine in 2017 gave 900 mg, twelve pellets, to 15 men. Levels fluctuated in the first two weeks and then stayed at or above 300 ng/dL through day 113. Forty percent were very satisfied and 26.7 percent quite satisfied, with one extrusion and one case of polycythemia. The authors state that the open-label uncontrolled design and the small, non-diverse sample limit interpretation.

Pellets carry the longest follow-up on red cell effects of any form. An analysis published in the European Journal of Endocrinology in 2010, covering 158 men treated for a mean of eight years and up to 21 years, reported an independent odds ratio for polycythemia of 15.0 per log testosterone (95 percent CI 2.5 to 90.8) after adjustment for smoking and age, and duration of therapy did not alter the risk.

Does the insertion site matter?

It did in the one study that tested it. A study published in Clinical Endocrinology in 2001 followed 96 men through 246 procedures using four 200 mg pellets. Extrusion was more common at the hip site, 15 of 125 procedures (12 percent), than at the abdominal site, 6 of 121 (5 percent), odds ratio 2.6 (95 percent CI 1.1 to 7.1). One operator had significantly fewer adverse events than the others (p = 0.006), and neither site nor track geometry influenced the pharmacokinetics.

Figures used on this page

What the evidence does not show

• The 2016 Andrology trial “lacked a placebo or an active comparator control,” so it does not show that the nasal route works better or worse than any other form.
• The fertility result does not extend past six months. The authors of the 2020 study in The Journal of Urology state that “long-term studies beyond 6 months are needed before we can safely prescribe nasal testosterone gel for men interested in fertility.
• The hematocrit fall of 0.8 percent on nasal gel comes from one retrospective matched cohort of 78 men followed for 16 weeks. No randomized trial has tested that comparison.
• The favourable acceptability figure for buccal testosterone, 90 percent rating twice-daily dosing acceptable, comes from a 2012 BJU International paper whose authors were affiliated with the product’s company and whose data were previously unpublished.
• The pellet polycythemia estimate is imprecise: an odds ratio of 15.0 with a 95 percent confidence interval of 2.5 to 90.8 leaves the size of the effect unsettled. The 2017 pellet study had 15 men, no control group and an open-label design.
• No public reason appears on record for the Australian implant cancellation beyond the sponsor’s own request under section 30(1)(c).

Frequently asked questions

Is nasal testosterone available in Canada?

Yes. Health Canada’s Drug Product Database, checked 14 September 2026, lists a nasal testosterone gel 4.5 percent delivering 5.5 mg per actuation, DIN 02450550, in marketed status. The same route is authorized in the United States under NDA 205488. It is not listed in the United Kingdom Electronic Medicines Compendium or on the Australian Register of Therapeutic Goods, so it is available in two of those four countries.

Does nasal testosterone preserve fertility?

A six-month single-arm study published in The Journal of Urology in 2020 in 60 men aged 18 to 55 found follicle-stimulating hormone in the normal range in 81.8 percent and luteinizing hormone in 72.7 percent, with total motile sperm count above 5 million in 93.9 percent at six months. The authors state that longer studies are needed before nasal gel can be safely prescribed for men interested in fertility.

Can testosterone pellets be implanted in Canada?

No. Implanted testosterone pellets have never been authorized in Canada and do not appear in Health Canada’s Drug Product Database at any status as of 14 September 2026. Among Canada, the United States, the United Kingdom and Australia, pellets are marketed only in the United States, under ANDA 080911. Australia’s 100 mg implant was cancelled at the sponsor’s request under section 30(1)(c) of the Therapeutic Goods Act.

Why was buccal testosterone discontinued?

The United States buccal product, NDA 021543, is listed as discontinued in Drugs@FDA, and no public regulator statement gives a reason. The tolerability record is the likely context: a paper published in BJU International in 2012 covering up to two years of use reported gum-related disorders in 5.6 to 16.3 percent of users and taste perversion in 3.0 to 4.1 percent. It was never authorized in Canada or Australia.

Does nasal testosterone raise hematocrit?

In the only study to compare it directly, a matched-cohort analysis of 78 men published in the Canadian Urological Association Journal in 2023, hematocrit fell by 0.8 percent over 16 weeks on nasal gel while rising 4.4 percent on cypionate injection and 1.7 percent on pellets. That study was small, retrospective and not randomized, so it is a single comparison rather than an established property of the route.

Related reading: testosterone products available in Canada and oral testosterone.

References

1. Rogol 2016. Natesto, a novel testosterone nasal gel, normalizes androgen levels in hypogonadal men. Andrology. PMID 26695758. DOI: https://doi.org/10.1111/andr.12137
2. Ramasamy 2020. Effect of Natesto on Reproductive Hormones, Semen Parameters and Hypogonadal Symptoms. The Journal of Urology. PMID 32294396. DOI: https://doi.org/10.1097/JU.0000000000001078
3. Gronski 2019. Efficacy stratified by baseline testosterone. Journal of the Endocrine Society. PMID 31428719. DOI: https://doi.org/10.1210/js.2019-00183
4. Rogol 2018. Subjects with seasonal allergies. Canadian Urological Association Journal. PMID 29603916. DOI: https://doi.org/10.5489/cuaj.4898
5. Reddy 2023. Prevalence of secondary erythrocytosis: a matched-cohort analysis of intranasal gel, injections, and pellets. Canadian Urological Association Journal. PMID 37068153. DOI: https://doi.org/10.5489/cuaj.8210
6. Ross 2004. European Journal of Endocrinology. PMID 14713280. DOI: https://doi.org/10.1530/eje.0.1500057
7. Dinsmore 2012. BJU International. PMID 22288877. DOI: https://doi.org/10.1111/j.1464-410X.2011.10837.x
8. Korbonits 2004. International Journal of Clinical Practice. PMID 15605676. DOI: https://doi.org/10.1111/j.1368-5031.2004.00383.x
9. Cavender 2010. Precocious puberty secondary to topical testosterone transfer. The Journal of Sexual Medicine. PMID 21114766. DOI: https://doi.org/10.1111/j.1743-6109.2010.02082.x
10. Kelleher 2001. Influence of implantation site and track geometry on the extrusion rate. Clinical Endocrinology. PMID 11678837. DOI: https://doi.org/10.1046/j.1365-2265.2001.01357.x
11. McCullough 2012. Multi-institutional observational study. The Journal of Sexual Medicine. PMID 22240203. DOI: https://doi.org/10.1111/j.1743-6109.2011.02570.x
12. Pastuszak 2012. Journal of Andrology. PMID 22403285. DOI: https://doi.org/10.2164/jandrol.111.016295
13. McMahon 2017. 900 mg (12 pellets) prospective study. The Journal of Sexual Medicine. PMID 28673432. DOI: https://doi.org/10.1016/j.jsxm.2017.04.734
14. Ip 2010. Trough testosterone predicts polycythemia over up to 21 years of pellets. European Journal of Endocrinology. PMID 19903801. DOI: https://doi.org/10.1530/EJE-09-0717
15. Health Canada. Drug Product Database. Queried 14 September 2026. https://health-products.canada.ca/dpd-bdpp/search/
16. US Food and Drug Administration. Drugs@FDA. Queried 14 September 2026. https://www.accessdata.fda.gov/scripts/cder/daf/
17. Electronic Medicines Compendium. Marketed testosterone products. Queried 14 September 2026. https://www.medicines.org.uk/emc
18. Therapeutic Goods Administration. Australian Register of Therapeutic Goods. Queried 14 September 2026. https://www.tga.gov.au/resources/artg
19. European Association of Urology. Guidelines on Sexual and Reproductive Health, male hypogonadism chapter. 2026 edition, limited update March 2026. https://uroweb.org/guidelines/sexual-and-reproductive-health/chapter/male-hypogonadism

This page is educational information, not medical advice. Testosterone is a prescription medication and a controlled substance in Canada. Talk to your doctor or pharmacist about your own situation.