Testosterone

Endpoint summary

Description of key information

Repeated dose toxicity tests are are available for testosterone and for esters of testosterone (testosterone enanthate, ZK 5137 and androstenedione) are reported.  Study summaries are included in this section for reliable tests conducted with read-across substances.  Results of tests with testosterone, published in secondary sources, are inlcuded in the summary discussion table below.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Study period:

10. Nov to 9. Dec. 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline GPL study

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

physiological saline

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

28/29 days

Frequency of treatment:

daily

Remarks:

Doses / Concentrations:
0-15-50-150 mg/kg bw per day
Basis:
actual ingested

No. of animals per sex per dose:

6/sex/dose

Control animals:

yes, concurrent vehicle

Critical effects observed:

not specified

Dose-dependently increasing effects such as increased body weight (>=15 mg/kg bw/day, F), atrophy of uterus and cervix (>= 15 mg/kg bw/day, F), pituitary gland (>=50 mg/kg bw/day , F) and adrenals (150 mg/kg bw/day, F), as well as increased erythrocytes and hemoglobin (>= 15 mg/kg bw/day, F). Increased liver weights (150 mg/kg bw/day, M+F) and increases of liver ALP and GLP transaminases (150 mg/kg bw/day, M+F).

Conclusions:

A No Observed Effects Level could not be established. The LOEL is 15 mg/kg bw/day, based on increased bodyweight and atrophy to uterus and cervix. These effects are not suitable to lead to repeat dose hazard classification, according to CLP or DSD.

Executive summary:

There are no available repeat dose toxicity studies on testosterone. Results of a study conducted with a structurally similar compound (androstenedione, ZK5155) are reported for read-across

The once daily oral administration of ZK 5155 to male and female rats over 4 weeks at doses of 0, 15, 50 and 150 mg/kg bw/day led to dose-dependently increasing effects such as increased body weight (>=15 mg/kg bw/day, F), atrophy of uterus and cervix (>= 15 mg/kg bw/day, F), pituitary gland (>=50 mg/kg bw/day, F) and adrenals (150 mg/kg bw/day, F), as well as increased erythrocytes and hemoglobin (>= 15 mg/kg bw/day, F). These effects are regarded to represent endocrine effects typical for a steroid hormone. Increased liver weights (150 mg/kg bw/day, M+F) and increases of liver transaminases (150 mg/kg bw/day, M+F) represent beginning organ toxicity. A no-observed-effect-level (NOEL) was not established. Females were more sensitive than males.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LOAEL

15 mg/kg bw/day

Study duration:

subacute

Species:

rat

Additional information

For testosterone, only limited data on toxicity was available. Further data was found for testosterone propionate and other esters and used for classification. Although repate dose toxicity test data are not required to fulfil the Annex VII obligations for a 1 -10 tpa registration dossier, summary data from the open literature are included here to provide support for classification conclusion. Read-across justification summary is attached to this endpoint summary.

Test system	Test Substance	Application	Dose/Duration	Effect	Literature
Male and female rats	androstenedione	Subcutaneous	over 4 weeks at doses of 0,5, 15, 50 mg/kg	The once daily subcutaneous administration of ZK 5155 to male and female rats over 4 weeks at doses of 0, 5, 15 and 50 mg/kg led to dose-dependent effects such as decrease of thymus and testes weights, increase of organ weights such as prostate, seminal vesicles or uterus and related histological alterations which can be attributed to the endocrine action of ZK 5155 with partial androgenic, estrogenic and progestagenic action. Additional signs of general toxicity like decreased body weight gain, decreased food- and increased water consumption together with occurence of protein in the urine and increased kidney weight were observed at higher doses. Due to the onset of some of the described effects already at the low dose, a no-observed-effect-level (NOEL) was not established.	Steger-Hartmann, T. 2000 Systemic tolerance study of ZK 5155 in rats (M+F) after daily subcutaneous administration over ca. 4 weeks (28-29 applications). Experimental Toxicology, Schering AG ; Bayer Schering Pharma AG;TXST 19970102 ;2000-04-09
Rat	androstenedione	Subcutaneous injection	15 male and 15 female rats per group received doses of 2, 6 and 20 mg/kg once every 21 days over a period of 26 weeks.	Body weight gain was increased in females from the mid dose onwards, whereas high dose males showed a decreased weight gain compared to controls. A depression of total serum protein levels was found after 20 mg/kg in male rats and from 6 mg/kg onwards in female rats. Albumin and alpha-1 globulin levels were decreased in females from 6 mg/kg upwards. Testicular weights were decreased in all treatment groups without histological changes. In female rats liver weight increased in the high dose group, again without a histological correlate. Weight decrease of the ovaries, the uterus and the adrenals was noted in female rats from 6 mg/kg, onwards. An increased number of atretic follicles and absence of mature corpora lutea in the ovaries were seen in all animals of the high dose group and only one animal at the mid dose-level. This finding was associated in a number of animals with a minimal endometrial hyperplasia in the uterus. Minimal mammary hyperplasia was recorded either from 6 mg/kg in males or at 20 mg/kg in females	Huntingdon Report, SCH23/73587, 1973-11-07
Beagle dogs	androstenedione	Subcutaneous injection	Three groups of 3 male and 3 female Beagle dogs received doses of 2, 6 and 20 mg/kg once every 21 days over a period of 26 weeks	A slight tendency towards decreased levels of serum alkaline phosphatase in the 6 and 20 mg/kg groups was noted. In female dogs uterus weights were decreased in all drug treated groups, but without dose-dependence. The mean ovary weight in the high dose group was also decreased. A depression of follicular activities was noted in the ovaries of all treated females and in the uteri a similar "reduction in the development" was reported. In male animals an increase in prostate weights were observed in the 20 mg/kg group. Testes weights were decreased from 6 mg/kg onwards associated with suppression of spermatogenesis. Small areas of squamous metaplasia in the branchial remnants in the thyroid of one male dog in the mid dose group and one high dose female animal were considered to be related to treatment	Huntingdon Report SCH22/73613, 1973-11-15
Rats	androstenedione	once daily oral administration	4 weeks	The once daily oral administration of ZK 5155 to male and female rats over 4 weeks at doses of 0, 15, 50 and 150 mg/kg led to dose-dependently increasing effects such as increased body weight (>=15 mg/kg, F), atrophy of uterus and cervix (>= 15 mg/kg, F), pituitary gland (>=50 mg/kg, F) and adrenals (150 mg/kg, F), as well as increased erythrocytes and hemoglobin (>= 15 mg/kg, F). These effects are regarded to represent endocrine effects typical for a steroid hormone. Increased liver weights (150 mg/kg, M+F) and increases of liver transaminases (150 mg/kg, M+F) represent beginning organ toxicity. A no-observed-effect-level (NOEL) was not established. Females were more sensitive than males	Treher, M. 1994 Systemic tolerance study of ZK 5155 in rats (M+F) after daily oral (intragastric) administration over ca. 4 weeks (28-29 applications) Experimental Toxicology, Schering AG ,AG 16 Bayer Schering Pharma AG; TX 94121 ; 1996-11-11

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:

Study conducted according to international guideline and GLP.  

Repeated dose toxicity: via oral route - systemic effects (target organ) urogenital: other

Justification for classification or non-classification

There are four repeat-dose studies available for androstenedione, a read-across substance for testosterone. Although effects have been observed, the toxicological significance of these effects, atrophy of uterus and cervix, pituitary gland and adrenals), as well as increased erythrocytes and haemoglobin at low doses (>15mg/kg) as result of oral exposure has not been clearly demonstrated. 

 

Observed effects listed above are similar to those listed in Regulation (EC) 1272/2008 (CLP), Annex 3, Section 3.9.2.8., effects considered not to support classification for specific target organ toxicity following repeated exposure. 

 

Additionally, the dose at which potentially significant effects are observed (>150 mg/kg bw increase liver transaminases) is higher than the guidance values in Table 3.9.2 (Category 2= oral concentration between 10 -100 mg/kg bw). Effects observed at lower doses (2, 6 mg/kg bw) are the result of exposure via subcutaneous injection, which is not a relevant route for repeat toxicity classification.

In the absence of significant adverse effects or repeated-does effects that are considered toxic and based on the weight of evidence for repeated dose studies in testosterone and the read across substances testosterone enanthate and androstenedione, testosterone is not classified according to the Directive 67/548/EEC and Regulation (EC) 1272/2008 (CLP).