No. It's a waste of time because even miniscule amounts of most steroids are enough to keep your body from producing any testosterone of it's own.
In this study a mere 100mgs of Test suppresses natural levels totally, by week 5 or 6:
1: J Investig Med. 1997 Oct;45(8):441-7.
Testosterone suppression of the HPT axis.
MacIndoe JH, Perry PJ, Yates WR, Holman TL, Ellingrod VL, Scott SD.
Department of Psychiatry, College of Medicine, University of Iowa, Iowa City, USA.
BACKGROUND: Although studies have demonstrated the suppression of normal gonadal function in the experimental setting, the specific mechanisms by which androgenic-anabolic steroids impact male gonadal function remain ill defined. Following 2 consecutive weekly injections of an identically appearing testosterone cypionate (TC) placebo, subjects were randomized to a TC dose of 100 mg/wk, 250 mg/wk, or 500 mg/wk.
Following the last weekly injection of active agent the subjects received 12 consecutive weeks of TC placebo injections. RESULTS: Spermatogenesis was impaired by each of the doses of TC employed in this study, but the observed decreases in, sperm count were neither strictly dose dependent nor consistent between individuals treated with the same dose.
Basal leuteinizing hormone (LH) and follicle stimulating hormone (FSH) became undetectable 2 weeks after the start of 250 and 500 mg/wk TC injections and were lost within 5 to 6 weeks of starting 100 mg doses. Pituitary gonadotropin responses to leutinizing hormone releasing hormone (LHRH) disappeared more slowly with FSH responses being lost 1 to 3 weeks after the loss of basal FSH activity.
Leuteinizing hormone responses to LHRH appeared to be suppressed last, disappearing 4 to 6 weeks after FSH responses to LHRH. CONCLUSIONS: Exogenous testosterone-mediated inhibitory influences on the hypothalamic-pituitary-testicular axis were reversed following the cessation of drug treatment.
And in this study, 100mgs of Deca (a single shot) suppressed natural testosterone levels to nothing also:
1: J Pharmacol Exp Ther. 1997 Apr;281(1):93-102.
Pharmacokinetics and pharmacodynamics of nandrolone esters in oil vehicle: effects of ester, injection site and injection volume.
Minto CF, Howe C, Wishart S, Conway AJ, Handelsman DJ.
Department of Anaesthesia and Pain Management, Royal North Shore Hospital, University of Sydney, Australia.
We studied healthy men who underwent blood sampling for plasma nandrolone, testosterone and inhibin measurements before and for 32 days after a single i.m. injection of 100 mg of nandrolone ester in arachis oil.
Twenty-three men were randomized into groups receiving nandrolone phenylpropionate (group 1, n = 7) or nandrolone decanoate (group 2, n = 6) injected into the gluteal muscle in 4 ml of arachis oil vehicle or nandrolone decanoate in 1 ml of arachis oil vehicle injected into either the gluteal (group 3, n = 5) or deltoid (group 4, n = 5) muscles.
Plasma nandrolone, testosterone and inhibin concentrations were analyzed by a mixed-effects indirect response model. Plasma nandrolone concentrations were influenced (P < .001) by different esters and injection sites, with higher and earlier peaks with the phenylpropionate ester, compared with the decanoate ester.
After nandrolone decanoate injection, the highest bioavailability and peak nandrolone levels were observed with the 1-ml gluteal injection. Plasma testosterone concentrations were also influenced (P < .001) by the ester and injection site, with the most rapid, but briefest, suppression being due to the phenylpropionate ester, whereas the most sustained suppression was achieved with the 1-ml gluteal injection.
Plasma inhibin concentrations were also significantly influenced by injection volume and site, with the lowest nadir occurring after the nandrolone decanoate 1-ml gluteal injection.
Thus, the bioavailability and physiological effects of a nandrolone ester in an oil vehicle are greatest when the ester is injected in a small (1 ml vs. 4 ml) volume and into the gluteal vs. deltoid muscle. We conclude that the side-chain ester and the injection site and volume influence the pharmacokinetics and pharmacodynamics of nandrolone esters in an oil vehicle in men.
ERGO, when you are "TAPERING" your body is NOT RECOVERING AT ALL. A mere 100mgs will keep you 100% suppressed at the end of your cycle!
Thus, I feel justified to conclude that tapering will NOT do anything to keep gains, or speed your recovery. Tapering will provide a period where you aren't taking enough steroids to do anything, and yet still not recovering natural hormonal function.
Tapering will be a non-productive period that keeps your hormones suppressed and doesn't "ease" your transition into PCT at all, because you are NOT RECOVERING ONE IOTA OF YOUR NATURAL HORMONES while you are tapering.