Yes, it is probably possible but not optimal. See the attached current American College of Sports Medicine position stand on resistance training. In the middle of Table 2 on p. 700, it summarizes the evidence-based optimal exercise prescription for achieving muscular hypertrophy.

Dear Dr. Helmi

Using less than 6 reps at 70-80% 1RM not good enough to develop muscle hypertrophy, and this articles will assist you :

• The Mechanisms of Muscle Hypertrophy and Their Application to Resistance Training
• Effects of Resistance Training Frequency on Measures of Muscle Hypertrophy: A Systematic Review and Meta-Analysis
• Designing Resistance Training Programmes to Enhance Muscular Fitness A Review of the Acute Programme Variables
• Single vs. Multiple Sets of Resistance Exercise for Muscle Hypertrophy: A Meta-Analysis
• Effects of Low- vs. High-Load Resistance Training on Muscle Strength and Hypertrophy in Well-Trained Men
• Effect of Repetition Duration During Resistance Training on Muscle Hypertrophy: A Systematic Review and Meta-Analysis
• The Effect of Inter-Set Rest Intervals on Resistance Exercise-Induced Muscle Hypertrophy
• Volume for Muscle Hypertrophy and Health Outcomes: The Most Effective Variable in Resistance Training

This is a great book discussed this point :

• Schoenfeld, B. (2016). Science and Development of Muscle Hypertrophy. Human Kinetics.

I hope the best for you.

Moustafa Tantawy

Dear DR. Helmi, in addition to the number of repetitions indicating the volume (6 reps) and the intensity of the effort (70 or 80% 1RM) it is necessary to specify other factors, , for example the time under tension (TUT) during each repetition given that if the eccentric phase is more long and the phase concentric is short well obtained an specific adaptation, whereas if it is done on the contrary it obtained another adaptation, likewise the density applied between the series must be in accordance with the previous parameter since it will directly affect a hypertrophic response mediated mainly by nervous adaptations or by increasing the cross section, as a result would depend on the target population and the level of experience in strength training with overloads.

Dear Dr. Helmi,

I am trying to resume all the answers, I think that all responses have reason. Maybe it is possible to write other important variables for increase hypertrophy. The volume and the intensity that you asnwered, could produce hypertrophy, but it i think that is not the best form to hypertrophy training. For this reason, I send you a review from a great researcher at Hypertrophy field.

Schoenfeld, B. J., Ogborn, D. I., & Krieger, J. W. (2015). Effect of repetition duration during resistance training on muscle hypertrophy: a systematic review and meta-analysis. Sports Medicine, 45(4), 577-585.

Best regards