There is some studies regarding usage of oral and inj version of winstrol.
The effect of stanozololon nitrogen retention in the dog.
Olson ME,Morck DW,Quinn KB.
Can J Vet Res. 2000;64:246-248.
Animal Health Unit and Gastrointestinal Sciences, University of Calgary, Alberta.
The objective of the study was to determine the influence of either oral or intramuscular administration of stanozolol on nitrogen retention in dogs by using a non-invasive 15N-amino acid tracer technique. Ten healthy, intact, adult male sled dogs received either stanozolol tablets, 2 mg/dog PO, q12h, for 25 days (Group 1, n = 5) or an intramuscular injection of 25 mg of stanozolol on Days 7, 14, 21, and 28 (Group 2, n = 5). A 15N amino acid (5.27 mmol) was infused intravenously into each dog on Day 0 (before stanozolol treatment) and on Day 31 (after stanozolol treatment). Urine was collected by catheterization from each animal 3 times daily for 3 consecutive days. The 15N-urea enrichment in urine was determined by high-resolution mass spectrometry and the total amount of urea in the urine was determined. Both oral and injectable stanozolol resulted in significant (P < 0.05) increases in amino acid nitrogen retention compared to pretreatment values. Oral stanozolol increased nitrogen retention from 29.2 +/- 8.2% to 50.3 +/- 9.2%, while stanozolol injection increased nitrogen retention from 26.6 +/- 9.9% to 67.0 +/- 7.5%. The response to intramuscular administration was significantly greater than the response to the oral dosing regime. Stanozolol increases amino acid nitrogen retention in dogs, as has been previously observed in rats. This action of stanozolol may be beneficial in dogs under stress of surgical trauma and chronic disease.
Now if we summarize :
So the oral dose was 28mg/week and the injected dose was 25mg/week. And the injected dose was far better at increasing nitrogen retention (67.0% versus 50.3%). This makes it about 33.2% better (roughly speaking), so if I extrapolate, it means to see the same effects as 25mg of injected stanozolol per week, you'd need to take about 38mg of it orally.