https://www.jwfacts.com/watchtower/blood-transfusions.php
Haemoglobin
Haemoglobin is what makes blood blood, as it carries the oxygen. It is also a major component of blood by weight, accounting for 33% of red blood cells and 14% of whole blood. As such, to allow haemoglobin effectively makes the Watchtower's entire blood policy meaningless.
1992 - Specifically Forbidden
“It would be right, of course, to avoid products that listed things such as blood, blood plasma, plasma, globin [or globulin] protein, or hemoglobin [or globin] iron.” Watchtower 1992 Oct 15 p.31
2000- Indirectly Allowed. With the Watchtower 2000 Jun 15 stating that fractions of the four blood components are allowed, haemoglobin was indirectly permitted, being a fraction of red blood cells. The same conclusion could also be drawn from the 2004 chart.
2006- Specifically Allowed. In the Kingdom Ministry 2006 Nov p.5, a work sheet specifically stated that haemoglobin is a personal decision.
For the history of WT stance on blood transfusions, jwfacts.com has a wonderful piece documenting this history of the blood doctrine over time till today. I always check to see how things are changing regarding using hemoglobin-based products made with expired human blood and others with animal blood. "