This is going to be pretty detailed so for those who've seen my thread on the other board by all means skip this topic since the message is pretty much the same (albeit with more data).
For others who simply cant stand reading long essays of scientific mumbo jumbo - skip to the conclusion
There is no specific "age" with regards to steroid use but, IMO, there is an age range of around 23-25.
Since we don't know how mentally developed the newbies posting here are, it is always better to go with the safer option of 25.
Here's why....
- A group of guys were treated back in the 60s & 70s with Sustanon 250 for 1 1/2 years in order to stop them from getting too tall - this was seen as a social disadvantage back then.
They then did a follow up 21yrs later to see if there were any lasting side effects compared to base levels of untreated men:
http://press.endocrine.org/doi/abs/10.1210/jc.2010-0435
"High-dose sex steroid treatment of boys does not affect their fatherhood or semen quality, as assessed after a mean follow-up of 21 years; however, serum testosterone levels are significantly reduced in androgen-treated tall men...
The treatment of tall stature is based on the understanding that exposure to gonadal steroids leads to epiphyseal fusion of the long bones during pubertal development.
"Leydig cell function was significantly affected by androgen treatment. In treated men, both serum testosterone and non-SHBG-bound testosterone levels were significantly reduced compared with untreated men. We hypothesize that the decreased T levels may be caused by reduced Leydig cell growth during puberty and suboptimal functioning of the Leydig cells in later life."
What does all this mean?
- Steroids can stunt your growth; this is one of the ways they were used in a clinical setting decades ago.
Therefore it should be obvious that cycling before 18-21 is a bad idea (no, not everyone magically stops growing at 18) but this alone doesn't justify the generic "25" recommendation.
- Good news is that fertility doesn't seem to be affected in the long term BUT your HPTA clearly doesn't recover fully either judging by the lower test levels.
- The main theory at the moment explaining why people don't recover after cycling concerns Leydig cell dysfunction, a problem that has no solution to it outside of TRT.
Now some of you will say that the risk of not recovering has more to do with overall dosage & length of cycles rather than age right?
That would be wrong - its a combination of age, dosage and cycle length. The Leydig cell theory is key to understanding why people shouldn't cycle before their early-mid 20s...
http://www.springer.com/cda/content/...66-p173728262.
"The precursor cells for adult Leydig cells begin their transformation at approx 10 yr of age, and differentiation is complete by 13 yr of age....During puberty, the number of adult Leydig cells increases and reaches a maximum of 5x10^8 per testis in the early 20s..."
Considering your Leydig cells don't stop developing until your early 20s, and Leydig cell dysfunction appears to be the main reason for not recovering from AAS, I don't think its a stretch to say that starting AAS before your early 20s INCREASES the risk of AAS-induced hypogonadism.
And THEN you have the fact that steroids do impact brain development:
http://www.ncbi.nlm.nih.gov/pubmed/25986964
"This multimodal magnetic resonance imaging study of the brain compared 10 male weightlifters reporting long-term AAS use with 10 age-matched weightlifters reporting no AAS exposure...
AAS users had larger right amygdala volumes than nonusers (P=0.002) and reduced rsFC between right amygdala and frontal, striatal, limbic, hippocampal, and visual cortical areas."
And the brain, a pretty important part of the endocrine system, isn't done developing until your early-mid 20s anyway...
http://www.ncbi.nlm.nih.gov/pubmed/11698594
"In this study, we conducted detailed spatial and temporal analyses of growth and gray matter density at the cortical surface of the brain in a group of 35 normally developing children, adolescents, and young adults...
Fourteen children (7–11 years; mean age, 9.3 ± 1.3 years; 7 boys and 7 girls), 11 adolescents (12–16 years; mean age, 13.8 ± 1.6 years; 6 boys and 5 girls), and 10 young adults (23–30 years; mean age, 25.6 ± 2.0 years; 5 men and 5 women) were studied...
In this report...we have mapped the spatial distribution of late brain growth and demonstrate that it does indeed continue in the frontal and posterior temporal lobes during the postadolescent years regardless of whether individual differences in global brain size are controlled."
Interesting, but completely coincidental, that the postadolescent group had a mean age of 25...
AND the impact of brain development MAY be stronger when its not yet fully developed...
http://www.ncbi.nlm.nih.gov/pubmed/23274699
""Studies in both humans and animal models indicate that AAS exposure during adolescence alters normal brain remodeling, including structural changes and neurotransmitter function... The evidence suggests that the use of AAS during this critical period of development may increase the risk for maladaptive behaviors along with neurological disorders."
So considering the brain isn't fully developed, and steroids do have an impact on different aspects of your brain, and this impact may be stronger when the brain isn't fully developed...it seems like a good idea to NOT interfere with the process.
Conclusion
- Steroids can stunt your growth.
- Leydig cell dysfunction is the main theory explaining why some guys don't recover post AAS cycle.
- Leydig cells are not done developing until the early 20s.
- AAS does alter certain aspects of the brain, implications of this are uncertain.
- Brain development continues until the early-mid 20s.
- The impact of AAS on the brain MAY be stronger when the endocrine system isn't fully developed.
- Based on all this, it makes sense to err on the side of caution and recommend an AAS starting age of 25